I vote that you should stay out of their business, only bcuz you know that your mom is currently depriving your dad of sex. Because of that, your mom is already breaking her marriage vows, and your dad absolutely has a right to have sex. If his wife (your mom) is refusing to have it with him, then he can always have it with somebody else
This is nobody’s fault but your mom’s. And I’m a woman. you will understand more when you’re older
I know you probably feel like “if someone doesn’t give you sex you should just divorce them right?”, .... but the thing is, when there’s kids involved and a house and money, it’s not always that easy. Your dad made a choice to get his needs met in secret, without hurting your mom. Your mom put him in the impossible position in the first place. And she’s clearly using him for his money. So what else can he do?
Also, your dad probably still does love your mom. He is getting his sexual needs met elsewhere, but he doesn’t want to leave your mom outright.
Also, your mom is obviously cheating on your dad too. It’s not like her needs suddenly just evaporated and disappeared. She’s cheating also. She’s probably just more sneaky about it. Maybe she does it at work or something.
Like they say, if a spouse is not having sex with you, they’re getting it somewhere else