Clownfish Strange Behaviour. Mating, Pairing or Fighting

My bigger Clownfish Marley is constantly chasing poor small Clownfish Bob all day/night long and being an angry bully! And then the bigger one starts to dance (?) I am not sure if they are mating/pairing up. poor Bob is not attacking Marley back just tries to quickly swim away and hide, but she wont let him be.