I've never had terrapurpura, but what I have read seems to indicate that they spawn in a harem-type fashion, with one male courting and breeding with multiple females...so no "pairing up" in the sense that we think of with most cichlids. My balzanii are also harem-breeders; they began to spawn a couple weeks ago as soon as I put a heater into their tank to kickstart the spring warm-up, but I don't see very much in the way of courtship or displaying or aggression...just a couple of females carrying around a mouth full of eyeballs, visible when they turn towards the front of the tank. I've yet to see a clutch of eggs on a nest, even though the eggs take a few days to hatch and only then does the female take them into her mouth. The tank is heavily scaped with wood and rocks, and the eggs are always laid in hidden locations.
Most of the typical cichlid activity we expect to see is related to selecting, preparing and especially to defending a nest site, and then later defending the fry. With these harem spawners, the male doesn't do very much; the female tends the eggs and fry and at least in my tank doesn't really direct any particularly aggressive attention to the other cichlids, livebearers, catfish, etc. in the tank. The whole breeding cycle is pretty subtle compared to the gladiatorial-arena-style action that would be seen with most cichlids.