This is when you're having sex with your girlfriend, and when you pull out to finish, her cats enter the room and you accidentally jizz all over her cats.
Friend 1: Last night i was having sex with the girlfriend, but when I pulled out to cum on her chest, her cats got in the way and I got cum all over them.
Friend 2: Sounds like you performed an exploding kitten
A card in Exploding Kittens used to get rid of a played card. Say this if someone uses an Uno Reverse Card on your insult, but be aware that they can say it back.