How do I avoid attending my uncle's church?

From a female CFB reader

I am in my final year in the university and am staying with my aunt (my mum's younger sister) whose husband is a Pastor of his own church with 18 members. I am from a Conservative Baptist family and I'm not cool with his Pentecostal way of doing things. My question is this; do I have to attend his church? If no how do I tell them without offending them?