Where is your line?

OK, so I have told Marc that I'm saving sex.
Tonight, he says, "so, what exactly don't you do?"

I buried my face in his chest!
I said, "I knew you were going to ask me that. You haven't crossed any lines yet. I would let you know if I was uncomfortable."
He says, "This is killing me! I just wasn't sure."

I didn't know how to answer him.
Finally, I told him where my line was.
He said OK.

I'm glad that he can be an adult as apparently I cannot.