When you see a fine girl walking by, you yell refill so that other guys stop and check her out.
Hey "refill!" (everybody turns and looks)
It is a derived from the idea of purchasing a soda at a restaurant and having unlimited ReFills to your hearts content.
*in terms of sex, a ReFill sometimes confused as a booty call, but instead is the close sister of a booty call*
A ReFill is having open sex access to ex-girlfriends or other girls who'm you've taken their virginity from thus allowing them to be attached to you indefinately.
Jeff: Who are you calling?
Dave: Ex-Gf. I need to get laid.
Jeff: Ahhhh, I too enjoy ReFills.
The act of shitting into a gaping asshole immediately following anal sex
After having anal sex with my partner I gave her a refill.
For people who suck at poker. When you lose all of your all-important 'internet money' on a poker site, you can refill your online 'bank account' to get you going again. You usually get 2 refills a day. Once they are gone, you'll need a new poker account to get more play money. Refills are the last grasp of a poker 'no-one' becoming a poker 'someone'. Sadly, this does not apply in real life.
'Garry, I just went all in with four kings!'
'Did ya win!?'
'Nope...lost to some jew wearing a cowboy hat'
'Time for a refill....'
'Garry, want a beer?'
'STFU! Can't you see I'm refilling!'
'Ms. Johnstone could do with a refill'