(n,v) To rely on pumping inertia to stay hard after ejaculation. This is to allow for a partner to climax if they have not, or to achieve multiple orgasms.
"Dude last night I blew before your mom, so I let her ride the buttercoaster for a while."
"I had to buttercoaster that chick for an hour before she finished."
"Buttercoastered!"
"I had to buttercoaster that chick for an hour before she finished."
"Buttercoastered!"
by TrickyBillyNumber5 December 1, 2005