DEAR ABBY: My only sister, "Carolyn," is getting married in two months. I'm ecstatic for her. She and her girlfriend turned 50 this year, and this is the happiest I have ever seen her. They are perfect together. Carolyn asked me to be her maid of honor and I gladly accepted. I am also decorating for her small wedding and reception.

When I received my wedding invitation last week, I was shocked and saddened. It was addressed to me and my kids only. My significant other, "Greg" (the kids' father), and I were married for 22 years and divorced three years ago. We have had some tough times but did reconcile. Even though we are divorced, we stayed together and never split households.

I have no idea how to tell Greg. I asked Carolyn if excluding Greg had been an oversight, and she said she would just prefer that he not be there. I can respect that, and I don't want to cause any drama or take anything away from her day.

Does this seem appropriate? My feelings are hurt, and I could have used Greg's help with things. How do I tell him he's not invited? -- IN A WEDDING QUANDARY

DEAR QUANDARY: Tell Greg the same way you told me. And after you do, don't be surprised that the relationship Greg has with Carolyn and her wife will be more distant than it has been.

It's possible that when you and Greg divorced, she developed a dislike for him that didn't abate after you reconciled, and it's sad that she chose this occasion to display it. Personally, I think her choice is one she'll regret in the future, but neither you nor I can change it.

DEAR ABBY: I'm a high school student, but it's not easy for me. Studying is hard at home because I just want to goof off after a long day at school. My grades are OK, but I'm worried that if this continues they will slip.

Then there's my eating habits and fitness. My school lunch period starts late in the day, so it's hard to stay satisfied from breakfast. When I get home, I'm still hungry and eat whatever's around, not usually healthy. And sitting all day at school doesn't help my fitness. Recently, I decided to have only a cup of water or soda until dinner, but I'm not sure that's healthy. Exercising at home doesn't happen because I'm either goofing off or doing homework.

Finally, there's my sleep habits. I go to bed at 8 or 9, but I have to wake up at 5 the next morning. How can I have good grades, be fit and be rested while having fun, too? -- MULTI-TASKER IN NEW HAMPSHIRE

DEAR MULTI-TASKER: If you arrive home with low energy, put on some walking shoes and go for a walk/jog or do some other form of exercise. When you return home, your mind will be alert. Then, have a piece of fruit with some cheese or a boiled egg. This should hold you until dinner. Water is healthy, and you should be able to drink it in unlimited amounts.

After you have had your snack, get your homework out of the way. If you do, there should be an hour or so in the evening for you to "goof off" before bedtime without feeling guilty.

DEAR ABBY: I have a question about how to handle a situation with one of my grandsons. "Rory" came to me recently to talk about religion. His mother is Christian; I am not. He asked what I thought about his mother forcing him to go to church. He has many doubts about Christianity.

I tried to understand Christianity for more than 50 years, and about 20 years ago I found peace with the faith I now practice. My daughter doesn't want me to talk to her children about my path.

My question is, how do I address this issue with my grandson without confusing him even more? Any help would be appreciated because I don't want to go against his mother's wishes. -- FOUND MY PEACE

DEAR FOUND YOUR PEACE: Answer your grandson's question honestly. He asked you what you thought about his being forced to go to church. He did not ask you how you found your peace -- or if you did. Sooner or later, he will find his own peace, and probably the same way you did -- by searching for it. Do not push him -- or pull him -- in any direction and keep the peace with his mother.

DEAR ABBY: My sister and her husband are well-to-do, but cheap. They recently invited themselves to stay three nights in our snowbird condo on their way to a vacation in the Caribbean. My wife and I hosted them, and during their stay we went out twice for dinner. Both times my sister was quick to request separate bills. In the meantime, we had provided lodging and all their other meals for them.

I am offended that they didn't show appreciation for our hospitality by at least taking us to dinner once. I have wanted to confront my sister about my feelings, but my wife has vehemently told me I shouldn't. What would you suggest? -- UNEQUAL IN PENNSYLVANIA

DEAR UNEQUAL: I see two ways of dealing with this. Keep your mouth shut, avoid confrontation and the next time your sister tells you she's coming for a visit, roll up the welcome mat saying you already have other plans. Or, tell your sister how you feel.

Personally, I think it would be healthier to express your feelings, because your sister's and her husband's behavior was rude. It shows that because people have money doesn't necessarily mean they have class.

DEAR ABBY: For many years I have been depressed about my father's opinion of me. Dad died 30 years ago thinking I was a screwup who would never amount to anything, and at the time it was true.

Since his death I have turned my life around. I have been married for 38 years, raised a fine son and I am successful in my career.

Still, I can't get past his feeling of disappointment in me at the time of his death. It haunts me daily that I was a loser while he was alive. Any advice to stop feeling guilty? -- REGRETFUL SON

DEAR SON: Not everyone matures at the same rate, and you may have been a late bloomer. Try telling yourself that you are sorry for whatever your sin of omission was, and then give yourself a dose of forgiveness.

If that doesn't do the trick, then instead of torturing yourself, discuss this with a licensed mental health professional. Remember, no one can change the past. We can, however, change the present, and by doing so, positively affect our future.

DEAR ABBY: I am almost 13 and I'm struggling with a lot of different things. I was adopted when I was a baby, so I never lived with my birth mother. That's probably a good thing, but I am having angry feelings toward her that I wish I wouldn't have. Those feelings are also being directed at friends and family members.

I'll think I have forgiven my birth mother for what she did, and then all of a sudden, I realize I never really did. I don't want to grow up being bitter all my life. Do you have any advice for me? -- NEEDS HELP IN INDIANA

DEAR NEEDS HELP: Yes. It is important you understand that birth mothers love their babies very much. When a woman places her child for adoption, there can be legitimate reasons for it. She may have been too young to raise a child, without the means to properly support it or addicted to drugs or alcohol. Your mother may have wanted you to have a better life than she had and felt another family could give it to you.

When you are older, you can do a search for her and find out the reason for yourself. But in the meantime, stop blaming her -- and you, your friends and family will be happier.

DEAR ABBY: I'm really confused about what to do about a couple of situations. I'm a 17-year-old high school senior and I have feelings for a 23-year-old single father. We have talked on and off over the past year. He said that once my 18th birthday came around he was going to "make me a very happy girl."

After I recently told him I was afraid we might not get together when the time came, we stopped talking. Now the mother of his child is back in the picture, and I'm glad for the baby's sake. I don't know for sure they're getting back together, though.

My second issue is about my feelings for a 20-year-old college student who's going away to an out-of-state school. He claims he's not the best guy for me, but I don't believe that. I told him I liked him regardless of what he says. I think he likes me, too, but it's not always clear. What should I do? -- SCATTERED IN CALIFORNIA

DEAR SCATTERED: For the next year or so, your first priority should be your future -- and I don't mean with a man. Before becoming seriously involved with anyone you must complete your education and establish some economic independence.

You were right to speak up about your concerns regarding your relationship with the first man you mentioned. That there is another woman in the picture -- even if she was in the background -- would have meant complications. Whether or not they get back together, the fact they have a child together means she may always be a presence in this man's life -- or could pop up at any time and cause disruption. Clearly, right now, he has unfinished business with her.

As to the second issue -- this young man may like you very much, but when a man tells a woman he is not the right man for her, what he usually means is that she is not the right woman for him. He may want to do what I'm advising you to do -- complete his education before becoming romantically involved. Or, he may feel the "chemistry" isn't quite right. If you accept it and move on, you'll save yourself some heartache.