My wife and her coworker

My wife used to spend a lot of time with a coworker of hers. He had asked her in a text at 1 o'clock in the morning while she is in bed next to me if it was bad that he wanted to impregnate his coworker. My wife just laughed and said that he was just crazy and told me that I don't have any thing to worry about that they were just friends and that was it. 8 never wanted to be controlling so I didn't really say anything when they started to spend time together outside of work. My wife would say that she was going out with some friends from work so I would always say okay. But somehow out of the group of people she went out with she would always end up being with him. Sometimes he will come to my house and get her. She would say that they were just going up to the store but they would be gone for 2 or three hours and she would leave her phone at home to. There were several other situations like this that happened over the years but she always said nothing physical ever happened. But I don't know, I mean I trust her but I just wanted to ask for some opinions.