I am sure no other civilization, not even the Romans, has showed such a vast proportion of ignominious and degraded nudity, and ugly, squalid dirty sex. Because no other civilization has driven sex into the underworld, and nudity to the W.C.
The chief cause of unhappiness in married life is that people think that marriage is sex attraction, which takes the form of promises and hopes and happiness - a view supported by public opinion and by literature. But marriage cannot cause happiness. Instead, it is always torture, which man has to pay for satisfying his sex urge.
Life is serious all the time, but living cannot be. You may have all the solemnity you wish in your neckties, but in anything important (such as sex, death, and religion), you must have mirth or you will have madness.
The usual sniggering examples of animal behaviour were brought in to explain cheating. Funny how the behaviour of shrews and gibbons is never used to explain table manners or road safety or gardening, only sex. Anyway, it was bad Darwinism. Taking the example of a monkey and applying it to yourself misses the point that animal behaviour is made for the benefit of the species, not as an excuse for the individual. Being incapable of sustaining a stable pair and supporting children is really not in the interests of our species. Neither is it really in the best interests of the philanderer.