Jack Dempsey Rubbing

[GrakFu]

Not sure if this is a Chiclid question or a diseas question...
Male JD rubs on everything in his corner. By his corner I mean the portion of aquarium he likes to breed in. By rubs I mean he scrapes either side of his head, from the corners of his mouth to the gill plate edge. It may be the whole span if he has enough room to maneuver, or just a small portion if he is in tight quarters.
He only seems to do it when he is colored up for mating or after a water change. He has been doing it for roughly 4 months. He didn't start until he started growing fangs. Initially it was 2 fangs on the bottom, I would consider them canines. He now has four total with the two newer teeth filling the gap between his canines.
His mate shows no signs of rubbing and they've been housed in the same aquarium from day 1. The turtles are also unaffected. Of course reptiles are not fish so could easily be a selective parasite.
So, any wisdom here? Mating ritual, marking territory, parasite or maybe he's just teething...

[mewickham]

Is he just moving gravel around? Cichlids commonly love to push it away to clear a spot for breeding.

[GrakFu]

No gravel. Very large rocks, and pvc pipe. He can't move either. Bare bottom tank with native flatstone decor.