In many species, males pay for sex. For example, among black ticked hanging flies, an amorous male will present a female with a nice, juicy insect and then copulate with her while she distractedly enjoys her meal. If the female finishes before he does, she simply walks away. Game over. If, on the other hand, he finishes first, he snatches the insect away and tries to woo another female with the leftovers.
Author: Steve Stewart-Williams