Am I over reacting?

does anyone else get aggravated when your having sex with your husband/significant other and he finishes first knowing you didn’t and then can’t continue having sex? I was waiting on him to get home from work because I was in the mood and then that happened and now I’m just not in a good mood because of it. Normally we finish at the same time, or I will directly before he does. But when we were in the middle of it and I was getting somewhat close to finishing, our son knocked on the door so I got up for like 10 seconds and then got back into the bed with my husband and realized he had already finished before I got up and he can’t just start back once he ejaculates. it takes him a little while before he can have sex again after, like several hours or so. Would anyone else feel this way though? I’m just disappointed. Sorry if this sounds selfish of me. I’m just not sure if anyone else would feel the same or am I over reacting?