AITAH Hurt my fiancées masculinity

I (26F) have been dating my boyfriend (19m) for about 6 months now. Three months ago he asked the question and I said yes. He is not very experienced, but I have very specific kinks.

Have been good and we decided to wait until marriage. My sex drive is way higher than his so we have been doing everything but. It has worked out fine so far.

Well around Christmas I had a family member pass away and I closed myself off. Been yo-yoing on emotions but his dad helped me through it. We are talking again and went on a few dates so we could reconnect.

I have been feeling powerless and wanting to reclaim something. So last night I teased my boyfriend over and did some power play. At the time he loved it. I can dirty talk with the best of them.

This morning he wanted to talk. Said I went a bit far and he had been thinking about all the things I said last night. I think bedroom talk and relationship stuff are separate and tried to explain it as fantasy play. He feels that I hurt his masculinity.

I laughed. I sorry I don’t get it. Masculinity is such a dumb thing to me. He got super mad and even threatened to cheat on me so he could get it back.

My main question is, what the fuck is masculinity and is it a real issue? How can I give him it back and do you think he was serious about finding someone else?