need advice (kinda long)

So I havent really been on OH alot lately, but I figured that this would be the best place to try and get some adivce on some personal issues that I am having.  So a little back story I've been friends with my friend Mike for about 5 years now, and we know everything about each other and I was one of the first people he came out to a few years back.  He pretty much became a part of my family, to the point that when we have a holiday my family is surprised if he isnt there.  Once he came out he felt better about himself and lost about 100lbs over the last few years which is good, but since he started to date more it seems like everytime he gets a new "boyfriend" he puts me on the back burner.  I put boyfriend in quotes bc with Mike it seems like he has a new bf every other week, it got to the point I started to call them the "boy du jour".  So last october i turned 21 and Mike was still only 20, so because I am the oldest out of all my friends I had to really wait to go out to clubs and bars until they turned 21.  Most of them including Mike turn 21 in august, so I've had to wait a good 8 months.  So this whole summer I've havent seen him bc he got a full time internship during the week and works alot with that, and fills up his weekends with these parties.  And for my graduation party was july 4th and he left early.  Which pissed me off.  But tonight I was talking to him and I was like so what plans do you have for your 21st? and he's like "Oh my friends are taking me to a gay bar for karokee, then the next day im going with other friends to anotehr gay club then to Ptown for the weekend."  And I didnt say anything but I was thinking well... what I dont get an invite?  like i thought we were friends and your not going to invite me to spend your birthday with you? Like he knows I dont care wether we go to a gay club straight club or whatever! But like I dont know, I dont know if im getting pissed at this for no reason, but its like we talked about his birthday since mine back in October, and even recently and im like I dont get why he's leaving me out of this big day.  And im starting to think that he might get embaressed because Im overweight still, I know this might sound silly but I think he doesnt want to include me because of this, just cause I know alot of gay guys are into there image and how skinny they are.  Like mike is so skinny now that my cousin said that he looked good (which he does) but asked me if there was something medically wrong with him to be so thin. I tell him all the time taht he needs to gain weight because he looks aneroxic.  Also it might be because Im not gay or lesbian and he doesnt think Ill fit in, and its like I think thats a reason why he doesnt hang out with me or invite me places bc everything he tells me which party he's going to it involves a gay party or "boyfriend" type person.   

Sorry this was so long,any advice would be helpful.  I just don't know what to do.

(hugs)  All I can offer is my personal experience.  This age-group can be EXTREMELY hard to get through with friendships intact.  People are trying to grow up, lead their own adult lives, while trying to juggle old friendships and sometimes people get left out (as you have seen).  I have lost pretty much every friend I had from high-school/college era because I grew up and they, frankly, didn't.

I am so sorry you're having to go through this because I know how it can hurt when someone you considered your best friend like, completely disses you.  In Mike's defense, did he know you were waiting for him to turn 21 before you went to celebrate the big birthday? 

However, you're astute to wonder if maybe he is more into his "image" now.  It's entirely possible.  I don't know him, obviously, but I can see it being something that could happen.  We used to affectionately refer to gay guys who were way thin and into their images as "manorexic".  Anyway, he's probably dealing with a lot himself, if he's lost all that weight and playing the field so much.  You know, from this journey, that when people lose a lot of weight they can start to question who they even are anymore.  Add that to the normal questioning people have for simply being a newly-minted adult and, well, some people don't handle it as well as others.

If Mike is truly a great friend you want to keep I would sit him down and nicely explain you were hurt that you didn't get an invite, being such a close friend of his.  Who knows, maybe he honestly thought you would be uncomfortable or wouldn't fit in?  But you'll never know if you don't talk.

I will say this though, as someone who was a doormat for way too long.  Give him three chances, and three only.  If you get blown off, left out, or otherwise treated as less than a friend more than that, it's time to say goodbye.  Sad, yes.  Harsh, definitely.  But you're worth more than that.

I am more of a straightforward person... Im at a point in my life I just ask questions instead of sitting around miserable. This is your friend - talk to him... you could start off by joking about his birthday... is it a 'gays only' bday party? or 'my invite must have gotten lost' or something - or you could be more direct and tell him you feel hurt because he didnt invite you.
As for putting you on the back burner with guys, thats really typical... a 'new love interest' no matter how du jour is exciting and fun, you get a high when you first meet somebody so you want to be around them all the time, sounds like it fizzles out for him, he goes back to his friends, meets another boy and starts over again... while its sucky to be the friend who keeps getting pushed aside its just what seems to happen - especially at that age.
You have to decide what type of friend this person is and if you want to keep them in your life. At this point it sounds like its more 'this guy I know" then "this is my friend" by the way he is been treating you... there is nothing wrong with 'friends' like that as long as you understand thats the way the realtionship is. Just dont sit around waiting for him to call etc, and dont always be there at the drop of a dime.. its not worth it to keep getting hurt. Go out and meet some new people that value you as a friend and treat you the way you want to be treated.

THANKS girls. your advice helped me see things differently.  It gives me some things to think about how I want to go about this.  Thanks alot!

You've had wonderful advice from everyone!!!  Good luck in your decision, sweetie.

I would just talk to him, and tell you how you feel.  By the way, I'm stealing the "boy du jour" line, lol

Ok i think i might... and totally take the line its such a great line!