How to get through to him

I (45F) was at work and my fiancé(49M) came to pick me. I was in my room working when I saw him walking in. He was upset saying he was out the office door for a bit and the door was locked.

I let him know the door has been getting stuck recently after we had had a break in the previous month. I myself used my key to enter because i wasn’t able to open it.

He said no your coworker locked it. We are 4 staff onsite, 1 male and 3 females. I let my fiancé know I needed 10 minutes to finish what I was doing and we could go home. He said he would wait in the car, but I cleared some space for him to wait in my room with me.

Lateron He repeated your coworker locked the door with you inside I don’t like him. ( again there were 4 people in the office) I reminded him we have been having problems with the door. to which my fiancé replied no im not talking about the bottom lock he locked the top lock. (I don’t know how he knows which lock was locked from the outside) I didnt reply because I didn’t know how to respond to that. He started accusing me of f***ing my coworker. I kept asking him to stop but he kept saying that and I yelled at him to stop and what was wrong with him. He is still arguing with me about it a year later saying I messed up our relationship by being upset with him and not telling the other guy off( I’m the manager at the site)

This is not the 1st time he’s come to pick me and we just had an office get together at the movies where I took my fiancé along. So he’s met my coworkers many times and never said anything before

He refuses counseling, or to listen to anything I say, I don’t know how to get through to him