No reason to stop that relationship Tridoc. Just be who you are. A good man. Father. Friend.

The rest will take care of itself between you two.

And yes I would tell him.

I would say your daughter is having an affair. I am trying to protect my family. I ask that you support our marriage. Support your daughter but do not support ADULTRY. I wish to remain friends for you have become a father to me. Support our marriage.

And then leave it at that.

Speak from the heart.

Take Care.

Try to get some sleep tonight.

It will be hard.

Flowers always make people better, happier, and more helpful; they are sunshine, food and medicine for the soul.
unconditional love is awesome!