She also tells me its her time to be selfish and do for her now that the kids are older.
If they were 22, 20 and 17, I MIGHT agree somewhat (altho that then raises additional issues about what kind of example she's setting for them as young adults), but your kids are too young to have their mother out of the house at all hours.
When my wife was having her affair, she came home once after 2am, after saying "I won't be late" and never calling or texting to tell me otherwise. When she got home, I made sure all of the lights were off, inside and out, and the house was locked up tight. I thought about even arming the security system, but I didn't want to wake up our kids if she set it off.
In any even, MESSAGE RECEIVED -- she never stayed out that late again.
