I need advice, asap, please help! :(

Gi

So I have a bestfriend, a boy bestfriend, and we’ve been like this for a few years now, no funny business at all. In the past, my ex, which idk if you guys have “that one ex” if you know what I’m talking about then you know, but anyways I was so in love with my ex and things didn’t work out (we had a toxic relationship) and so we’ve been broken up for half a year now but still keep contact for some reason, anyways, back to the point. So me and my bestfriend are reallly close, I tell him EVERYTHING that’s going on with my life, and all the drama, and everything. That’s not all, my bestfriend has been to family birthday parties, met my whole family, gets along with my parents and siblings very well. My sister, has been begging me to date him, and I just never saw it going that way. But then as it kept getting pushed on me, I actually thought about it, and was thinking like maybe it isn’t a bad idea, because before I thought I was in love with him but I told myself naw, your tripping. So I started thinking about it and was like...well...I already know his mom dad siblings and get along very well with them along with his grandpa. Then I was like idk. I won’t say anything. So one night, he had decided to sleep over by my sisters house with me one night because he was going to watch her kids the next day, (yes, they get along THAT much) and so we had to sleep on the couch but on separate couches, we were laying down. I got up to get my phone which was laying on the edge of the couch he was laying on. So I walk over and I go to walk back and he starts play fighting with me. That’s what we do alllll the time. And so it was like 2:30 am and we started fighting and then outta nowhere, he kissed me. Then we both went in again and sorta started making out. Nothing else happened but the day after, we kept kissing. Anyone have any idea on what I should do? We are both 18. Please help any suggestions will be helpful thank you so much.