help! its complicated!!!

ok so me and my crush were with one of his friends at the park and we we're just kinda chilling and talking and he passed me a note that said "will you go out with me?" so of course I said yes but then I had to go home. after I went home his friend asked him out and he said maybe. long story short he had to make a choice between me and her and he chose her. they dated for two or so weeks and then the girl ran away and cheated on him. 3 weeks go by and now he asked me out and I said yes again. but I'm not sure if it's right. he chose the other girl over me even when he asked me first. I don't know if I should trust him or if it's gonna last long.

I need opinions!!