Is this possessive attitude?

When I told my Bf that an acquaintance was trying to hit on me, he stormed like anything, it was like his anger literally SHOT UP, he used the worst abuse in our native language that none of the sober men would ever use infront of the ladies, that I cant even tell ANYONE. He started to ask me his name and address etc, to KIDNAP him and beat him up like a dog, I COULDN’T BELIEVE that, couldn’t even decide if he was serious or not, in that confusion I told him that I was just kidding and it was nothing serious. I was extremely disappointed with his behavior but he was extremely apologetic. But this incident had given me such a shock, that I tried to be careful of telling him anything related to a guy interested in me. Because his most frequent and apparently serious means of threatening anyone to do him or me harm was to KIDNAP him and beat him. I cant believe he can do anything of this caliber but just to be on the safe side I B CAREFUL. I am alienating from him because this suppression kills the feelings in me.