Should i get back with him or just give up???!!! plz help xx?

me and my boyfriend broke up twice nd he came back to me in the first time but in the second time he didn't and its been about 3 weeks or so since the break up and i've tried almost everything to get back with him but it just wouldn't work and he was speaking rudely to me at school byt then sometimes he would look at me sweetly and i don't know what to do i mean the only thing we've done is holding hands and touching my bum in a teasing way with clothes on and by the way i am a bit young for my age and have only gone out with him for two months and was devastated at the break up but we just had to because he's cousin is coming to skool in september and if she tells he's mum then we're both busted and i really wanna get back with him but hes acting weird by speaking rudely but then looking across at me like sweetly and i dont know what 2 du plz help!!! xx