Sounds like normal behaviour. Initially when you introduce the new convict I would expect them to be locking jaws. Once they get used to each other that probably won't happen much, but the male will probably chase/follow the female around and they'll be a lot of gill flaring.
I think it probably is courting behaviour, but could be just aggression. Some more obvious courting behaviour would be digging nest sites, following each other around the tank and the male "dancing/shaking" to impress the female.