What is Yo Ville? I guess some relationship site? Anyway, YES, he is cheating - if he actually isn't, he is about to, shortly, and he is definitely looking to cheat. Otherwise why does he need to be matched on Match.com?
I would keep it as neutral as possible....bring up what you know, tell him why you were touching his phone to begin with...and let him do most of the talking. If he denies it, make him prove it to you - demand access to his Match and his YoVille account so that you can see and read everything. If he squirms at that, then you've got your answer for sure.
Then, it is up to you want to want to do....for some, cheating is a dealbreaker in the marriage. Is it for you? If so, then leave. If not, then agree to go to therapy to talk this out and resolve the issue.