Girl problems...?

So I recently converted to Paganism, and I tried to hide it from my girl. But one night, my sect was worshiping a tree and my girlfriend walked in on us when we were sacrificing a pigeon to Woden and she got totally creeped out. We talked it out and everything was back to normal but now the entire pagan church is having a m ritual at Stonehenge and I need to go to sip the Blood of Thor from the Dixie Cup of Life but my girlfriend says she'll leave me if I do. So, what should I do?