"first of all, one thing I've never thought of you as is a slut. And I respect you being direct. so I'll do the same and tell you honestly, as far as you and I go, you would probably only ever be the other woman."
Most Helpful Guy
He is being honest and trying to make it sound nice. Basically what he is saying is that as far as sex goes you are okay, but to be tied to you - not going to happen.
He is only in the relationship for the sex and lack of being tied down to you.
Kick his ass to the curb, get a man that wants to be your one and only!