My partner doesn't live with me but we usually spend several nights per week together, when it works with kids/jobs (both divorced). At times in the past he's 'joked' I may have another man. I'm always flippant in response, it's not really worthy of an answer.
This week he's been away with work all week, which he really didn't want to do. One evening I went out with a friend but hadn't mentioned to him. He called while we were out but I didn't see. I had dinner/drinks with friend and then answered partners next call at 10pm. He 'joked' were you with your other man and seemed bothered Id not answered earlier. I explained I'd been at the pub with female friend, he asked a few questions. He keeps mentioning since, about 'you with your other man'. I've tried 'joking' back, 'yeah one for every day of the week'. But he doesnt let it drop, it keeps cropping up. He phones often, seems worried.
Why is he doing this? Genuine suspicion? Insecurity? He is the one who went away for work, not me, otherwise I'd be seeing him! For reference, we did split up a few years back and both dated others. We have been a stable couple for a few years now though.