Do I have the right to be mad about my boyfriend having 3 drunk (girl) friends sleep in his bed with him?

This past week, I randomly asked my boyfriend where his 3 friends slept at his house last week. They are 3 girls that are quite promiscuous, but I am confident that nothing physically happened. However, I have told him before (over a year ago) that I was not comfortable or cool with him having other girls sleep in his bed while he was also sleeping there.

He responds that he didn't just have one, but three "bed guests." I told him I was not happy with it at all, and he bluntly said he was sorry for upsetting me, but not for what he did.

Is it okay for me to be upset? I realize it's not a huge deal, but I was so insulted and it's important to me that he doesn't spoon with drunk female friends, but he just doesn't get it anymore. What do I do?