Husband eating lunch with female coworker

So I just want to get everyone else’s opinion on this even though I’m pretty sure I already know the answer. My husband has been eating lunch everyday with one of his female coworkers alone in her car. To me this is totally in appropriate. His justification is that he knows her husband. I don’t know her, I don’t know her husband so to me this is inappropriate. I asked if he would be ok if I ate alone in my car with a male coworker he doesn’t know and he says it wouldn’t be ok bc there’s a cafeteria at my work. There is also a break room or cafeteria at his work and if he doesn’t want to eat there he has is own vehicle to eat in. Also I only found out because I saw a text even tho he swears he told me. Pretty sure I’d remember. Am I overreacting?