Ok big edit since people are focusing on things that doesn't really matter to my problem.

My ex and I were together for 14 months and we broke up for various reasons. We were broken up for around a month and during that time, he had a one night stand. He came back to me last Friday, said he missed me and love me so we agreed to try again. I stupidly asked too many questions and now I know too much and I can't stop picturing them having sex in my head and it's driving me nuts. Every thing else is going great between us so far and I don't want to fuck it up. Any advice?

Edit: Please know that I'm not trying to make him look like the bad guy. I know he had every right to do so. I just want tips and tricks on how to stop thinking and picturing them having sex.
user
I can't stop thinking about my ex having sex with another girl while we were broken up.
assistant
Ok big edit since people are focusing on things that doesn't really matter to my problem.

My ex and I were together for 14 months and we broke up for various reasons. We were broken up for around a month and during that time, he had a one night stand. He came back to me last Friday, said he missed me and love me so we agreed to try again. I stupidly asked too many questions and now I know too much and I can't stop picturing them having sex in my head and it's driving me nuts. Every thing else is going great between us so far and I don't want to fuck it up. Any advice?

Edit: Please know that I'm not trying to make him look like the bad guy. I know he had every right to do so. I just want tips and tricks on how to stop thinking and picturing them having sex.
user
Thinking about my ex having sex with another girl and don't want to fuck up our relationship.
assistant