Thinking of not talking to my cousin Trevor anymore

He was such a bad person when he was addicted to cocaine and living in Florida town I was living in…he would cheat on my friend, Denise even though Denise and her family lived with him in her parents mansion…he was totally self centered then, and he is now…but now he is a new father of a baby boy about three years old but his wife I wonder if he is cheating…I don’t want to find out…so I am thinking of just not answering the phone when he calls anymore…he calls every couple weeks…but I am discovering I really still hold it against him for being so selfish.