If it's dancing, let her have her fun. My man has two left feet, and doesn't do club, parties or alcohol. I'm the opposite, and do go out and dance my night away. Nothing sinister in having a hobby you enjoy and your partner doesn't. Blocking once interests because you don't enjoy it is toxic. Not everything is a backstory for cheating, and not everything has to be done as a couple. You can have separate breaths.

If it’s dancing specifically and not the going out part that she misses, there’s probably somewhere nearby where people meet up to dance regularly that you could sign her up for. You don’t always have to do everything together, and while she is out dancing you could invite some friends over or work on your hobbies or something.