my cousin and i have been sleeping together

i want to tell the story of how me and my cousin had sex, i am in no way shape or form promoting, fetishizing or endorsing incest, but i have kept this secret for a long time and i think that writing this anonymous on reddit might help me.

when i was 15 and my cousin 16 (both boys) we were in our peek of hormonal changes, we were very close we would do everything together and have sleepovers a lot, one night we stayed up late and we were having different conversations about a lot of things and as boys are we started to compare our sizes, one thing led to another and we rubbed each other cocks.

and i thought that was the last time we would do it, but i was wrong. we liked it a lot so we tried to do a lot of other stuff, we gave each other handjobs, blowjobs and after many of those things my cousin asked to put it in. at first it burned but after i liked and i remember think i shouldn’t like this, because he’s my cousin but i did.

we stopped for a while, we saw each other less and when we were 18 and he 19, he asked me out on a bar. we drank some alcohol but we were sober and he offered for me to sleepover at his place because his parents weren’t home, and that night we had a really passionate sex, we did it a few times but i feel guilty.

i feel really bad about it and i want to call it off but idk how to break that news to him, any advice?