There was just a segment this week on the Today show, Tuesday, I think. Usually the TV is on in the background while I'm getting kids to school, etc, but I remember it caught my attention. A close girlfriend of mine had her marriage broken up due to a cheating husband. I tried Googling, but this is what I could find in a hurry on the Today Show webpage:
To catch a cheat, follow your gut. More than likely, it’s telling you something is off. There are tons of tips on the signs of straying, but some are universal. Your honey starts to take extra care in his or her appearance — buying new clothes, working out, new haircut. They start meticulously deleting sent messages and keep their inbox pristine. Sex is either feast or famine or just plain different. Their cell phone never leaves their side. You get the idea and then it starts to gnaw at you.
“The interesting thing, if it’s going on, you’re not going to get any peace until you know, confirm or disprove what you suspect,” said the Queens, New York-based Houston, who 15 years ago discovered her then-husband was cheating on her with three women. She’s interviewed thousands of investigators, therapists, academics, victims and perpetrators since then and wrote a book, “Is He Cheating on You?”
They also had a Private Investigator who said that a couple of the signs are - he's not interested sexually (too busy, too tired), or he has a new sexual "routine", he might be trying out new things he's learned.
My friend's ex cheated while deployed in the Military. They were married 17 years. While the affair was happening, he would write her emails about how great she was, great mom, great wife, etc. When he got home, his guilt ate away at him so he started to be very mean and verbally abusive.
OK, after all this I'm not saying he is, I'm just saying don't ignore your gut. If you're laid off, I would suggest trying to trail him with out being seen or if you have a little cash on hand, hire a Private Det. My friend did this even after her husband had ended the affair & found out the woman's address/phone. My friend is pretty bold & a theater major, so she called the lady and got all the answers her husband refused to say (even during divorce proceedings), basically if the other woman got pregnant from the affair, if she had any STD's, etc.
As for your husband's dad cheating, Family Systems Theory suggests that he's more likely to follow in his footsteps.
I just checked Amazon about the book mentioned above. I would definitely buy it if I were in your position. Ruth Houston, "Is He Cheating on You?" Also her website:
http://www.infidelityadvice.com/