While many are familiar with mother-in-law horror stories, one man is dealing with an awkward father-in-law situation.

In an anonymous letter to The Guardian, the man admitted to having had a “bi phase” before meeting his girlfriend.

“Five years ago, I went through a bi phase and used to sleep around with pretty much everyone that came along, including other men,” the letter reads. “This changed when I fell in love with my new partner, who is everything to me.”

The unidentified man even had plans to propose to his girlfriend, but it all fell apart when he finally met her parents.

“Halfway through lunch [I] realized that I had slept with her father,” the letter continues.

As if that wasn’t complicated enough, the father gave him an ultimatum.

“When my partner and her mother were away, he told me to end it with his daughter,” he wrote in the letter. “I’m obviously in love – shall I just ignore him, or tell my partner?”

 Author and relationship expert Susan Winter said they must have an open conversation because there is a chance that the relationship may survive. She said there should be some idea of openness with his female partner, otherwise, they would not be attracted to each other.

Winter explains that this type of situation is becoming more and more common as younger demographics are becoming more open and fluid with their sexualities. In fact, almost one in every 10 self-identifying straight men have gay encounters. Of those people, 70% are married.

“As our society evolves, we are having greater freedom to understand who we really are, independent of stereotypical roles,” Winter said. “We have to have a very honest conversation about our future because marriage is not going to look like what our parents had.”