"All loves have to die; of that there's no help.

My favorite way to end 'em

Is the orb weaver spider's, whose pedipalp

Enters the female pudendum,

Then dies on the spot, his corpse there still stuck,

Left for his rivals to curse it.

He would rather die than not get to fuck;

Personally, I reckon it's worth it!"

--TISM, "Everyone Else Has Had More Sex Than Me"

Spider sex is fascinatingly bizarre, but if you really want to be grossed out, look up bedbug sex. The female bedbug has no vagina analogue or other opening in which to leave sperm, so the male bedbug just kind of fucks away at her until he pierces or wears a hole in her exoskeleton and injects his sperm into that, where it floats around in her hemolymph until it finds her eggs. Female bedbugs are thus highly susceptible to coital infection, but those fuckers are nevertheless adapted for survival even despite our efforts to get rid of them.