The
amphibian analog of
coitus. During amplexus, the male is facing the female's back, with his front limbs grasping her waist. Amphibians have no
external genitalia, so all that happens is they release
sperm and
eggs at the same time.
Frogs sometimes aren't too picky about who/what they choose for amplexus. They have been observed making it with rocks, shoes, and animals other than female frogs.