Heather, glad to hear that the shale worked out for them.
Wilkes, mouthing like that is extremely typical of pairing activity in cichlids. You say that the female is dominant, but has now lost color and the male is chasing her. I said that I thought your fish looked young, and maybe the male is not ready to spawn yet. If the female has/had pink on her belly, she will most certainly be ready to spawn. Sometimes separating the fish for a week and then putting them back together will form a pair once they are put back together. I can't see the fish myself and have only your descriptions to go by, so I can't assess the situation in more detail.
I would suggest the you have ample coverage in the tank for the fish to get away from one another. Make sure that lines of sight are broken up so that one fish doesn't feel stressed if another gets too close. Give it time though. It could be something as simple as the female not wanting to pair with that male. Getting another male and putting it in there might be the best bet as it MAY encourage the pair to form a strong bond, but it may also be hard on the current male as the new male will most likely show aggression to a degree. I don't recommend keeping the unpaired male in the tank once a pair has formed.