Complex sentence: Unlike the male equivalent, autofellatio, which is known to be achievable by a small fraction of the male population, autocunnilingus was not found in a study of sexual humour based on transformation of proverbs.
Split into simpler sentences: Unlike the male equivalent, autofellatio, which is known to be achievable by a small fraction of the male population, autocunnilingus is not reliably documented to be achievable in real life. Autocunnilingus was not found in a study of sexual humour based on transformation of proverbs.