Nice fish, but not a 'mating pair', per se.
For one, mbuna's are polygamous or harem breeders (best kept in one male per several females gender ratio's), and don't really 'pair up'. They're a pair only in the numerical sense.
Secondly, those are two different metriaclima ('zebra complex') species there (an apparent kenyi and would looks to be a red zebra, hard to be certain from the photo). Any fry from the two would be hybrids (metriaclima lombardoi x metriaclima estherae).