A couple of the Urban Dictionary's definitions of 'Twink':
1) twink: An attractive, boyish-looking, young gay man. The stereotypical twink is 18-22, slender with little or no body hair, often blonde, dresses in club wear even at 10:00 AM, and is not particularly intelligent. A twink is the gay answer to the blonde bimbo cheerleader.
2) twink: In an MMORPG, a veteran player who makes a new character and gives a bunch of top-shelf equipment from their older, maxed-out characters to the new character.
I'm familiar with only the second definition, I'd never heard the first before...