Well I don't like to jump to conclusions and judge but that sure sounded like an affair to me. An older man texting a 19 year old girl six times a day, waiting for his wife to go into the bath and then calling her up? Friends my @$$. HAHAHA. And for her to resign from the company is a pretty extreme thing to do if you didn't do anything wrong to begin with. Oh and let's say he didn't actually get to do the deed with her, but I guarantee everytime he was typing up a little text he was wetting himself.
I know if I was the one texting some guy like that and calling him up while DH was in the bath I'd be in big trouble.
Anywhooo like I said...I don't like to be judgemental or anything.