I have been going out with my boyfriend for nearly 2 years now but we have not yet met each other's parents. A few months ago we had a family wedding and my mother told me to bring him along but she makes me feel ashamed sometimes so I did not invite him. He talks about his parents and shows me pictures of them and they are really fit as they exercise etc while my mother weighs over 300 pounds and she does nothing to help the situation. She says that she is really in pain with her back and legs and when someone tells her to lose some weight she gets defensive and says that her weight is not causing the pain and doctors did not find any condition which might be affecting her pain and so she refuses to go to doctors anymore as she says they will just blame it on her weight.

I love her but she behaves really bad sometimes and makes me feel really ashamed, for instance in the wedding that we had the seats were all made of plastic and she made a scene of how selfish it is not to do wooden seats for people like her and she kept complaining until they had to take the wedding organizer chair and give it to her and she spent the night saying how sad and in pain she is everyday and I notice that people just get bored with her words every time (even I do as she complains EVERY DAY) . I would have died with shame if there was my boyfriend.

Now we have another wedding in a few weeks time and she keeps insisting that I bring him along, and I really want to since he might feel excluded if I do not invite him after 2 years but I feel afraid that she will behave that way and that he will think that she is crazy. Should I invite him and tell him beforehand that she is overweight etc or not?

Tell him all you want (and I probably would gently prepare him a bit), but FIRST you need to tell yourself that your mother is not you, and you are not your mother. She is not a reflection of you. She doesn't represent you.

I do understand what you are going through - I had a loud, demanding mother, and often felt embarrassed in gatherings.
When one friend met her when I was about 40 years old, the friend whispered, "She's worse than I expected," and I actually felt better, vindicated!

It can take a lifetime to really understand that you are not tied to nor responsible for anyone but you, unless/until you have children.

Invite him, and talk honestly to him, and maybe he will understand why you don't invite him to family functions. Fact remains though that you have never met his "lovely" family either, so whats up with that? Has he invited you to his family functions?

You both will have to meet each others families eventually, and be able to deal with them one way or another. How he finds out the truth about your feelings depends on YOU.

He did not have any family weddings in these two years but he did not invite me to his house to meet them. Should I say something about it? However, I do not consider meeting his/my parents that important since at the end of the day it is him whom I am dating.

You're right, all things in their own time I suppose, and maybe you both have not gotten to that point in the dating relationship yet to have that conversation, or take those steps. In that case no hurry, so don't worry about inviting him to your family wedding.

You have plenty of time to discuss whatever you want to ask of each other, whenever you are ready.