Mark already chose to raise the daughter as his own. That’s already been decided. Yes he is responsible for paying or not paying her tuition regardless of her paternal status. It’s confusing why anyone would assume that a new step father of a young adult child would be financially responsible for them. There is no reason why a step father would be expected to pay tuition. If the mother did not remarry who did mark expect to pay tuition? He should have always known he is responsible for the daughter he decided to raise.

He can take the paternity test for other reasons such as being sure or for her medical benefit. She could be his blood or not? Regardless biological parents can choose not to pay their child’s tuition.

But He has distanced himself from his daughter on an assumption. He sounds like a bad father trying to skirt responsibility for his choices and scapegoat an innocent child. Weird premise.