Someone help

So I have a friend, we have sex like it’s just wee got a good thing going. Like we vibe and all but we’ve never really talked about being together. We are kinda like Bestfriends but we have sex yk but anyways , every time we have sex I bleed right after. Like every time Idk if it’s bc it’s too big or idk bc his thing is big like bigggg. Like it doesn’t hurt or anything but it’s like every time. I’m 4’11 I weight about 180 . What do y’all guys think it is.