My uncle is very nice guy. he;s the type of guy that have a heart for everyone.I think like almost if not everyday he talks to his ex female friend of many yrs ago. They say they're just close because they have known each other since they were 21 yrs old and now they are 50. Their conversations are probably mainly about sex BUT they do talk about other things to. He tells her she need to leave the loser that she is dealing with alone. They do chat like they are friends from a long time ago.

My concern is they are talking on a regular basis and I know with her being single she will start to get attached to him because of the length of the time they've known each other and chatting almost everyday.

He even share some personal stuff with her. If he is working at home he will show her a photo of him on computer , once he was bbq for the holiday and he felt the need show her he is grilling. He doesn't like the type of guy she is seeing and want her to drop him.
This is the weird part. He asked her is there a video of her having sex with the guy and he want to see it cause it turned him on.

He is my uncle so of coarse not only me we all know of this situation.

Is he married?

OOPS! I see he is so would that not be the business of his wife to deem this appropriate or not, and what they talk about or if everybody knows then certainly she would too. Wonder how she feels about all this.

huh not sure of your answer

Married people have their own rules of good conduct and if the world knows of this close friendship then I'm sure the wife does too, so is this not the case?

She knows nothing of her . he feels it's innocent and keep it from her because they are close friends.They talk all the time tell each of there every move. they may be bit much in my opinion. He shows her photos of him

Hell to pay when she finds out for sure.