Having gay sex with step cousin?

He's 15 and I'm also 15 We live together on the same house ok this going to be a little long but please answer this I'm starting to like him ok so we mess around more than 5 times like we both gived head to eachother and we did a 69 he told me to suck he's d*** i said no but we were horny so i sucked him he did the samething to me he want it to f**** in the a** but i said no were not really cousins but we said we are he looks straight I'm bi i asked him if he was gay or bi cause we messed around a lot of times he said he said he was bi but i didn't believe him cause he was half asleep pleasr help me i really like him yhu think he's atleast bi pr gay? And yhu think he likes me also he's the first to ask to suck he's d*** thank you