Would you let your spouse go to a gym by themselves when they have a history of cheating?

My wife wants to join a gym and demands that she goes by herself. That would be all good and fine except for the fact she has a history of cheating in our relationship and demands that she goes by herself. I'm all for self improvement and her having her freedom but when she demands to go by herself then I start wondering. We don't have anything that we really do together hobby wise and I thought she might even just ask if I wanted to join her, but no. I know if I came up with this idea she would be asking a million questions even though I've never cheated on anyone. What do you think?