Aww, Amy, so maybe that's why he has been 'appearing' to be nice all over again!? Hummmm.
I was cheated on a few times and I recognised all the signs in the end - change of character/out of character gestures etc.
Change of mood - from not so happy, to something like too happy compared, things like that.
Well, although it's tempting to be a 'fake date' and you would probably know then, by responding to him, I think that mind games get dangerous and are pointless to be honest, because it just prolongs the agony for you.
You have found that he is there and that's enough to go on - no-one accidentally comes by those things and then keeps it going - it's deliberate.
If he is doing it online, what's he doing behind your back? If not being faithful to you, then he isn't gonna be faithful to those online either...
I would confront him over it, but you can choose your moment with it, without mind games. They just get too messy and things become more fraught than necessary. I feel it's always best to get it over and done with, otherwise too much bitterness can set in. Why should you make yourself feel like that, through him being unfaithful (if that is what's going on).
It's a bit in your face though, with him being on that online dating site in the first place.
I hope things are going to be ok for you hun and just keep yourself reminded that you are the sweetest person ever hun and you deserve respect or he isn't worth anything.
Don't be fooled anymore, if indeed, that's what's going on.
I would hate to see you hurt in that way or any other, with all the goodness in your heart that you hold for everyone.
Take care.
*big hug*