For folks who were asking about The Script, I think there is a thread on it, but I'll give it a stab for a partial list of cheawee (cheating weinee) behaviors.
Cheawee blames his partner in the following ways;
"You weren't making me happy."
"You did/you are ...." (fill in the blanks with incredibly petty compliants, usually about supposed failures in housekeeping, cooking, sex and appearance, showing how sexist he is.
"You're controlling." is also popular, and is almost always a projection, as the cheater is the controlling one.
Cheawee makes other self-deluded excuses, such as;
"It just happened! It wasn't on purpose."
"She seduced me."
The ever popular ILYBINILWY ("I love you but I'm not in love with you.")
"The heart wants what the heart wants."
"She's my soulmate."
"We have nothing in common."
"I deserve happiness. This is my chance and I'm taking it."
"She's really great. You'd like her if you knew her."
Following this the cheawee will either pretend he wants to reconcile, making all kinds of promises and shedding crocodile tears, or he will coldly show that he has detached and either leave immediately or expect to be allowed to stay and continue his affair right under your nose.
If it is the former, he will expect you to book all the marriage counseling appointments, and if he will even go (odds are not good) he will sullenly stare at his feet during the sessions or go on the offensive and repeat his blame-shifting and excuses. The therapist may enable him in trying to get you to accept blame and you will end up being double teamed by two emotional abusers. He may pretend remorse, but it will feel hollow because it is. He is merely trying to keep his convenient lifestyle, which is the lifestyle you afforded him by taking care of his home and children while he gallivanted about and focused single-mindedly on his career.
If he leaves immediately, expect to be the one to have to file for divorce. He is not anxious to pay child support/spousal support and will try to keep you from getting legal assistance by claiming he will take care of you and you can work it out privately. This is a lie. He'll oppose you at every turn.
He may demand 50% of child custody while paying almost nothing in support, but he will seldom use his 50% for long. He does not really want to take care of the children, he just wants to win. Expect him to break his promises to the kids and to be chronically late to pick them up/drop them off. He will cancel at the very last minute, even if you have planned and paid for a trip for yourself while the kids are away. This is done simply to mess with you. He considers it a victory every time he fucks up your life.
Bizarrely, he will chastise you if you are less than pleased with this conduct, spouting; "Why are you so bitter?" and "Why can't we be friends?"