Boyfriend’s uncle hits on me

A few nights ago, I (22) was at a family reunion with my boyfriend, and his drunk uncle (≈55) kept hitting on me. For like 5 hours. Making inappropriate comments, touching my legs, following me around everywhere and staring at my chest and butt, saying he wanted to make babies with me, etc. And doing it very publicly, even when my bf was sitting next to me.

I was extremely uncomfortable and kept hiding in the bathroom to get just a few minutes away from him. My boyfriend kinda laughed it off saying his uncle was harmless, and tried to distract his uncle so I could have some space. But this seems to happen everytime I see his uncle and it’s so uncomfortable.

What do you think I should do next time? I don’t want to be dramatic and overreact in front of my boyfriend’s family, but I shouldn’t have to put up with this for hours on end! And literally right in front of my boyfriend and his entire family 🙄