Major relationship problem.?

OK so we are just sleeping together, I'm 19 he is 28, and he is my boss, but a relationship between my position and his is allowed, however i want more but I'm too scared to ask if he does. he gets jealous when i mention other guys and he always ask who I'm texting but when i ask him he if he is jealous he changes the subject and when im rounds his lying in his bed with me he squeezes me like he really likes me. But i don't want to seem like this little girl pestering him (if you get me) but he also acts like nothing happening between us at work. and its my birthday in a few days and i really want him to take me out! such a mess Ive got myself into. what should i do?