I thought something new happened just now, the way you phrased that.
I'm sorry to say, but sometimes men just want sex, and I've seen too many times on here where the woman reads WAAAAYYYYY more into it than that, which (along with the obvious STDs concerns) is one of the main reasons I'm against ML while DBing, esp. where infidelity is involved.
I think your planned speech is perfect, don't get me wrong. I just think you weakened your hand considerably by having sex with him right before the confrontation.
What is it we say around here? "Believe none of what they say, and only half of what they do?" Your words SAY one thing to him, but your ACTIONS say otherwise.