Happy Birthday to You

Happy Birthday to You, also called A Sticky Situation, is an unmarked quest

Detailed walkthrough
Once given clearance to enter Little Lamplight by Mayor MacCready, the gate opens to display several kids gathered around a teenager wearing a red birthday hat.

Sticky has just turned 16, and it's time for him to leave Little Lamplight. When you speak to him, he tells you he wants to go to Big Town, where all the grownups go.

Once Sticky joins your party, you may give him weapons and armor, which he will then use to defend himself on the journey.

During the trip, Sticky talks quite a bit, sometimes making up stories presumably chosen at random. His stories follow a Mad-Lib template: similar stories repeat, with only about half the words changed. You can either put up with it, tell him to shut up, or kill him (this holds no Karma loss).

This quest is completed upon crossing the bridge to Big Town.

Behind the scenes
Two names exist for this quest. "A Sticky Situation" is the quest name given by the Fallout 3 Official Game Guide, while "Happy Birthday to You" is the name found in the GECK.

Bugs
Leading Sticky across the highway between Vault 101 and Big Town sometimes causes him to turn around and run away without warning. He will run down to ground level and across the wastes, following the highway for a while before disappearing.