The using of the fingers in a female's rear to loosen the hole up for further penetration. Much as working a settled choclate mousse into a whipped and easily spoonable concouction.
The character 'Chocolate Mousse' was a sensitive yet mucho black French mercenary in the 80's comedy film "Top Secret". Chocolate Mousse was often seen smoking a cigar and carrying large, inappropriate ordinance around in the film such as an 18th century ship cannon or a large oversized machine gun. In the 21st Century, Chocolate Mousse has become a cliche on internet websites such as fark and many people photoshop the character into stills from other films where he doesn't belong.
I tried to be fancy and squeeze the mousse from a ziploc, but it just became poop mousse.
Nel: Watch out for the dog doo
Ecid: Thanks. Hey, that reminds me of the poop mousse we had at Ard's place last night.