Intimate picture of female coworker

My boyfriend had 1 picture of a female coworker of his on his phone. She was in a bra and thong and she posted it on her story and he screenshot the pic to send it to his friend (who she is interested in) but he never sent him the pic and forgot to delete it on his phone. He blocked her on Snapchat and permanently deleted the pic. We have been together for over 7 years and this is the first time he has ever done anything like this.

I want to move on from this and he has apologized to me, he swears he has never done anything and never will and I trust him enough to forgive and move forward but I don’t know how.

I’m not stupid and I don’t want to end my 7 year relationship because of a stupid mistake he made. But I told him that if I find any reason to believe that he has been emotionally or physically cheating on me I would dump his ass in a heartbeat.

What I’m asking is for advice on how to move on. I don’t want to be that girlfriend who has to go through his phone, ask other coworkers about their relationship, be petty and get revenge, punish him everyday by making smart comments or being a bitch, but I don’t want him to think that it’s okay.

Hours later after we briefly talked about it, we were getting in the mood to f*** but as soon as we started getting intimate her picture popped in my head and I told him to stop. He stopped and laid me down and held me and told me he was sorry and is willing to do anything to make it up to me...

I want this feeling to go away so if you’ve ever dealt with a situation like this, help me out and give me some advice...what should I do?