[Lissa]

Any form of lustful or affectionate motions geared toward someone other than a significant other and are carried out is cheating. (I was in a relationship where I had to explain this to my boyfriend...luckily it didn't last much longer after that point)

Personally I'm a bit of a snoop so I would go to the pub and check it out for myself before taking her along, that way you will know for sure before she goes there and you can console her if the worst is true but don't confront him yourself, that's for her to do. His actions are VERY suspicious, but I try to err toward the good side and hope that he's just being misunderstood.

Or recommend marriage counseling, if he's cheating then he's finding something lacking in the relationship and with a counselor they can talk about it, maybe then he'll come clean on his own and they can decide then what they want to do and what would be best for their children.

I'd recommend the counseling before anything else now that I think about it. He's keeping stuff from her and there aren't supposed to be secrets in a marriage, that wall needs to be broken down if any semblance if a relationship is to be salvaged.