That's how my wife left me. I let her make love to anyone she wanted. One time I spied on her, and heard her say "Your cock is bigger than my husband's" I had not thought of that. But it excited me to see her fuck with other guys. Now I realize once she had felt a bigger cock than mine she wanted more of bigger cocks. Eventually she found a man she liked who had a bigger one. She kept seeing him time and again, until one day she came to our place with him and told me she was going to stay with him at his place... the divorce came later, at my request.