I really need ur help guys!!! I appreaciate any suggestions thanx ;)?

ok, here is my question. I got this job right i started like 3 months ago and my birthday was after my second week there and i went to work not expecting anything and then i find out that my boss has prepared for me this little party with cake and stuff. so everyone was kinda teasing me abut it cause they don't usually do that i mean celebrating other staff member's birthdays i asked my boss if they usually do this and he is like he started doing this so my concern is his birthday is coming up i didn't want to get him anything but my friend's were like it be rude to not get him anything and then they suggested that i should get him a keyring with his name on it but i was wondering if a keyring with his name,it will seem personal especially that everyone at work was kinda bitching about him preparing me that little party and that now I'm suspecting he has a gf so all i want is to make sure that this kind of present is NOT personal and not too formal i mean do u think it would be nice.