When did rachel and puck start dating
Puck decides to do the Single Ladies Dance because Quinn called him a Lima Loser.
At rehearsal, everyone is guessing why Quinn is acting so weird and he tells them that she may "Have a bun in the Oven" but tells them the father is Finn even though he knows it's his. During Halo/Walking on Sunshine, Puck stares at Quinn's butt.
When Will starts singing Bust a Move, Quinn walks away from Finn and when she does this Puck is shown to be staring at her.
Mercedes tells him to lay off, because Quinn chose Finn to be the father and he hurt Quinn enough.
During the glee members were singing Lean On Me, towards the end, Puck sings the lyrics "Call Me." and gives her a smirk, Quinn looking tempted bites her lips, nods her head and looks away with a smile while blushing Quinn continues to pretend the father of her unborn baby is Finn.
In Season 2, they rarely spoke or had much interaction, most likely because Quinn was in relationships with Sam and Finn, while Puck was in a relationship with Lauren.
In the episode I Am Unicorn, Shelby comes back to Lima with Beth.
Afterwards, Puck is visibly upset when Quinn goes to practice on Finn's wheelchair.