How should I tell this to my friend and how do I hide it from my other school friends?

Okay so my friend that goes to school with me apparently found out on my facebook that me and my friend had an interesting little talk. It did involve “sexual” sayings, but we were just playing around. I didn’t mean like he would take it like anything….I didn’t even know that facebook let you see my things with other friends….Now I’m panicking and I have no idea what to do or what to tell him….I’m really scared of what will happen. But the last comment my online friend posted was “Oh yeah I can give good B****Jobs” etc, etc….I didn’t really want him to say something like that…..But now my friend is getting all freaked out by this…How do I keep this talk between my friend and I away from my other friends and My friend I was talking to? I need some serious help…..