My Dad and my friend have erotic chats with each other on Facebook. Do I confront them?

[seneschal]

As an older guy, to get female attention like that from a much younger woman is very flattering. You need to try and understand his feelings before you go in with confrontations. You also need to think about the consequences should word of this get to your mother.
Its probably a mid life crisis for him and a thrill for your friend knowing she is such a turn on for her friends dad, its not so unusual so you shouldnt be angry with either of them but.......
Their relationship is ultimately doomed beacuase of the age difference but you wouldnt want your dad to lose everything because of it.
Its a tough call for you, maybe you should just have a quiet word with your dad and point out the things I've said and a quiet chat with your friend also.

I hope it works out ok for you all.