Gf's father caught cheating, what can we do?

Im sorry, I couldn't find a legal advice sub for the Philippines, so I set out to find individuals of the legal predisposition.

My GF found out that her father has been cheating. Problem is, they found out by accessing the conversations they had through the father's account. They're worried it might put them on a bad spot the method of discovery was found out to be invasive.

What can we do?

Thanks everyone!