She is not going out with OM, she is going out with a friend (who I am not keen on and think is a really bad influence on our sitch), but, I've no idea if A) she is actually cheating for sure, B) she is even still in contact with OM and C) if she is planning to meet him later, although she may not actually know that yet herself.

I will not give her money I don't think on this occasion, I've nothing to gain from it as I don't think it will be appreciated.

It's all so confusing, the not knowing which is what makes it so hard to not snoop. I won't don't get me wrong, but it's tough. If you can get through this, M saved or not, you will be a better person for it and that is what I must tell myself to keep me going.