“The tsetse fly Kama Sutra is long and elaborate,” said Eberhard, who described the 30-minute ritual during which the male rubs the underside of the female’s abdomen with his hind legs, sings to her by buzzing his wings, rubs her eyes with his front legs, and so on…
https://phys.org/news/2009-05-genital-door-cryptic-female-choice.html

Experimental demonstration of possible cryptic female choice on male tsetse fly genitalia
R D Briceño, W G Eberhard DOI: 10.1016/j.jinsphys.2009.07.001
Copulation behaviour of Glossina pallidipes (Diptera: Muscidae) outside and inside the female, with a discussion of genitalic evolution. R D Briceño, W G Eberhard, A S Robinson DOI: 10.1017/S0007485307005214
Cryptic female choice— η ικανότητα των θηλυκών να ελέγχουν το σπέρμα ποιού αρσενικού θα φτάσει στο ωάριό τους, κατά τη διάρκεια αλλά και μετά το ζευγάρωμα… ένα φαινόμενο με εξελικτικές συνέπειες…