First off, happy birthday! I hope you have a great time with your friends, despite the stress with your boyfriend.

I can kind of see where he's coming from, but... the thing is, it's your BIRTHDAY. The last thing he should be doing is pouting and making you feel BAD... about YOUR BIRTHDAY. Just my opinion, obviously, but that's where I stand.

Does he act like this about other things too, or is he otherwise generally pretty reasonable?

How did he react to your invitation to come over on your birthday, or to go out with your friends? What did he say when you told him that you'd rather spend a full day with him, not just see him for a meal?

Is there any chance that he had been planning some sort of surprise for you, and that his reaction is really because he's hurt that you made other plans (so he can't surprise you now)? Just a thought...

I hope it all works out, but most of all... I hope you get to enjoy your day!