To high five your fried/partner during a threesome to celebrate your sexual accomplishment.
So you and your friend got really shitfaced at this girls/guys house and they end up screwing you and your friend (a threesome) at the same time and to celebrate you high five your friend. ULTIMATE HIGH FIVE!!
by Gerald cuntzton November 10, 2007
The Ultimate high five is where two men are doing two girls doggie style and the two girls are making out, then the two guys high five over the two girls.
We were bangin those two chicks last night and did the Ultimate high five.
by Jonny Rage October 12, 2011