Let me start off, I have a boyfriend

although he’s in prison for a year or two. I smoke weed so I started going to the guy my boyfriend goes to which is one of his best friends.  One thing led to another

and now I’m having the best sex of my

entire life and I know its just “sex”, but I need to figure out how to stop it because

I’m sure I’ll go back with my boyfriend 

When he gets home. Any advice???