Male nursery web spiders avoid being eaten after sex by tying up their mate's legs with silk, scientists have found.
The bizarre spider bondage was observed for a study published in the Royal Society's Biology Letters journal, and the practice has been observed in at least 30 different spider species.
Female spiders are often bigger and more aggressive than males, and sometimes eat them before they can have a chance to mate. By covering the female in a tight web (also known as a 'bridal veil'), the male can extend his mating time and improving his chances of getting the female pregnant.
Arachno-bondage is well-known, but the recent study, conducted by Alissa Anderson and Eileen Hebets from the University of Nebraska, has brought it to public attention.
Focusing their studies on the Pisaurina mira, or nursery web spider, they tried to see what effect the web-spinning had on the spiders' chances of mating.
The researchers collected a number of the spiders, and temporarily blocked up the silk-spinning organs in half of them, preventing them from creating a web. The spinnerets of the other half were left untouched.
As the study found, the males who could wrap up their partners with web were far less likely to be cannibalised after sex, regardless of their size, and had many more opportunies for sperm transfer than their webless comrades.
Importantly, the males who wrapped up their partners were more likely to get away unscathed afterwards, too.
This may sound like a weird bit of foreplay, but as Discovery points out, it's probably just a scratch on the surface of strange spider sex stuff. There's over 45,000 species of spider around the world, and the mating behaviours of most of them have never been studied.
That leaves us with the worrying conclusion that there may be even weirder stuff out there - we just haven't discovered it yet.
