My uncle is creeping me out

I only see him on Christmas eve. Idk how to really put this. Past Christmas he’s done the same but let’s stick to this year. We have Christmas eve at my grandparents house and my aunt (my mom sister) her husband (my uncle) and my two cousins are there, and my mom obviously. We bought my dog and she needed to go outside so took her out and my uncle smokes so he came outside with me and we were just talking and he than tried to kiss and grope me. I just went back inside. Idk what to even do. Also I put this in Thai group because I could find a better group for the topic