My son is turning 31 and I think we should celebrate.?!

Depends, does he actually not like having parties thrown for him or is he just trying to say that it's not necessary, that's something only you would know.

I think it's nice, but some people really don't like having parties thrown for them, if that's the case, take him somewhere nice nice for dinner, I actually prefer to go somewhere really nice than have a big party myself.

I think it is more like..."you shouldn't have..." more than genuinely opposed to the idea esp if he likes to entertain himself. It means he is a social guy but also knows how many details are involved with party planning. So if you do something for him, I think he would want no-fuss and simple.

I would just have a simple backyard party or indoor buffet with your son's fav people, that is, close family and a couple of your son's friends. It's hard to say who because if you have a large family it can get out of hand fast but you don't want to hurt anyone's feelings either. Just do food, drinks, gifts, cake, ice cream. No big surprises, no themes, no funny hats or trick candles, no napkin rings. Take a lot of pictures and allow time for folks to just sit and visit! Have a kid video for younger guests.

OR if your group gets big, everyone meet up at his fav restaurant and everyone pays for their own family's dinner.

OR if your son is a man's man and cherishes his nights with his buddies for poker or watching sports or whatever...you could go around to relatives and collect video birthday wishes and present it to him at a guys only night where they do whatever it is they do. And his birthday gift is being allowed to spend his birthday doing that. Just his pals hanging out, no guilt, no expectations.

yeah

If so ... , why didn't You invite me ?!?
;)
thanks.