A second serving is when enough alcohol has been bought to last for the night, yet some participants unreasonably agree that more needs to bought. Doing so frequently results in various forms of tragedy (e.g. car accidents, arrests, or massive amounts of vomit).
"Almost everybody was asleep on the couch or the floor, but some guys went out to buy a second serving. They came back and barely drank what they bought, and ended up puking and sleeping in the bathroom."

"Everything was going cool, but a couple of guys felt that we needed a second serving. They went out to buy more, but still haven't come back yet."
by doctordrunk May 21, 2010
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