The wood-feeding cockroach may be the only known example of a species that practices mutual sexual cannibalism – both male and female nibble each other’s wings after mating
Source:
https://www.newscientist.com/article/2267476-cannibal-cockroaches-nibble-each-others-wings-after-they-have-mated/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home