Long story short.

Twelve years ago, in the space of a week, my wife’s father got caught cheating and the family business went into bankruptcy because he was way in over his head in debt. Mother in law stayed with him, there’s nothing in the relationship just companionship.

Went away for the weekend with him and my brother in law and when we’re on the plane coming back home, I go to make conversation with him and see he’s texting his secretary. Calling her “my sunshine” etc. I look away and try not to take notice thinking maybe that’s just normal talk for them but then when I turn back to talk he’s going through his WhatsApp and selectively deleting the flirty messages to her.

My brain tells me to do nothing and stay the fuck out of it, but I’m also acting weird around him. What would you guys do?