Living in the same house as my ex

I'm living with my best friends family for the summer and my ex just so happens to be her brother. This is very frustrating because I'm still sexually attracted to him. I've never had sex with him but I've always wanted to and it's getting harder not to give in especially when he's always touching me and getting close to me. I'm not mixing what he feels for me as actual interest and I am tired of playing his games but that doesn't keep me from wanting to jump his bones.