Well, he might have already done it - sorry to be so blunt.
I spent YEARS thinking "what if he just looked, was curious".
When I finally dumped him with newfound evidence he said he was "just looking".
I said (I remember this so clearly, because it was so calm, and I felt so much relief, it set me free):
"You are lying. But even if you were "just looking", you know that is enough for me to end this, yes?"
You are already upset and losing confidence in your body because of him. Believe me, it will get worse.
First time I had sex after our separation, my partner pulled right back mid way through. I felt awful, I wasn't doing it for him. I wasn't attractive, I didn't turn him on. I said "are you OK?", nearly in tears. He said, "fuck yes, too OK, I had to pull back I was about to come too quickly!"
That is what years of a husband being "interested" in prostitutes and not in you, can do to you 
Don't put yourself through it love. x