Is there any clear cut signs with infidelity

[RedHeadWife]

I honestly never had any clue that my H was having EA. The one thing I did *realize* after I did know was how close he kept his cell phone all of a sudden. Ended up checking it any chance I got, which wasn't often, b/c like I said he kept it w/ him at all times and found that he & chick from work were calling back & forth constantly. He denies that it was her, but I still don't believe that, but I've let it go. The other thing was that we all of a sudden had a yahoo! log in come up on the computer automatically when you logged on. I think maybe he had a yahoo! account and maybe was even looking at dating sites that way. I don't think I'll ever know for sure about that one. Don't care anymore; don't need details. He knows if he does anything again, he's gone for sure.