Horse outward similarity is an unreliable measure of relatedness. Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus". Horses can crossbreed with other members of their genus. The most common hybrid is the mule, a cross between a "jack" (male donkey) and a mare. A related hybrid, a hinny, is a cross between a stallion and a jenny (female donkey). Other hybrids include the zorse,
Clothed female, naked male Clothed female, naked male Clothed female, naked male (CFNM), or clothed male, naked female, is a genre of erotica based on the real or imagined interaction of one or more nude men and one or more clothed women. It is sometimes a sexual fantasy of women or men, depicting an exhibitionist or physique worship scenario. CFNM situations can arise in situations where a male disrobes as part of a male striptease, a medical examination, as a figure model for art students, or is forced to remove clothing as a punitive measure. In pornography or erotic writing, CFNM depicts a power