Happy Birthday Atlast!
Try and not let this get to you. This was the "drunk" in them talking. It is way easier for them to feel that "everyone" is happily drinking rather than having to see that maybe it's not really all it has been hyped up to be.
Call them in the early am and ask if they would like to go for a walk/run. Probably would have to leave a message. (only kidding about the calls)
Be happy with yourself and take care of yourself. Not lame, just better educated about what brings peace and happiness.