I really need boyfriend help!!!!?

There is this guy and we have gone out like twice. I have been the one 2 break up with him both times. It's cause he gets way 2 serious. I so love him again but he is goin out with someone else. We text and talk ALL the time. And we were texting yesterday and he said i was pretty hot and that he still liked me but not to tell his gf. We will end up going out again and i just need some advice on this: we r only in 6th grade and he wants 2 show pda at skool like hugging in the hall and me wearing his hoddies and all that. the BIG thing is he wants to kiss and i dont hink were old enough but i cant tell him that.