Boy problemmsss? Helpp!?

okay..sooo..im datin this guy named Jamie..i've liked him for..ehh..a month or so? And well..his girlfriend broke up with him sometime in August and we just started dating Saturday..And i feel like hes just using me to make his ex jealous...And non of my friends are helpin me with this! And this guy i;ve liked for a while finally is talkin to me and he was like ."How old are you? and i said "13.." and he said "I might date a 13 year old..but only you" and i was like awww.. but hes 16..and hes a trouble maker! my brother hates him and if my brother finds out i even know his name..Im dead..And i never catch Jamie lookin at me..I always catch him lookin at his ex. *Sam* and i always catch Larry starin at me with a smile on his face... Please helpp..?