hell......HAPPY BELATED BIRTHDAY! I am not really sure how I would handle this....some people just forget things like this, it's how they are and also it's not like you were throwing obvious hints or saying straight out that it was your birthday....and then he forgot. I think if you do bring it up, be playful about it yet get your message across. I don't think you should not say anything at all and let it go....that might make him feel even worse if he does find out and some time has passed, maybe asking you why you didn't say anything. I don't know if you talk daily or not but it's the weekend....maybe say in passing if he talks to you and ask if you have plans...you could always come up with something like " It was my birthday yesterday, I am thinking that I would like to do something special for it....just not sure what just yet"............take it from there. Hope this helps a little bit.