Wormdance

In the platynereis genus (Marine Bristle Worm) the female will get so turned on by her partner's erotic dance that, finally unable to restrain herself, she'll lose all conrtol. Consumed with sexual excitement, she'll bite off the sex organs of the male which are located in his rear end. (A kind of endless sex.) She swallows the sperm contained in this mouthful, and the sperm travels through her body to the cache of eggs and fertilises them.