How Snakes Fuck

I was just watching an installment in the Evil Bong movie series, where 1 character insults another by calling him something like “a pustule on a snake’s vagina.” This made me think, being me, “How do snakes fuck? How does a slithering tube get to another slithering tube’s vagina?” Here is what I found, and it’s pretty interesting:

http://www.bbc.com/earth/story/20170608-snake-sex-is-every-bit-as-peculiar-as-you-would-expect