Puck was sure that the only difference between being a friend of Finn in Sophomore year and being his friend in Junior year was going to be that they were older and Puck didn't fancy Quinn anymore and was done trying to steal Finn's girlfriends. What actually had changed, besides those things, was the fact that now being friends with Finn meant being friend with Kurt and see Burt Hummel every time he went over to hang out with Finn.
At first Puck had been almost afraid of Burt because Mr. H was a scary looking dude but after a year spent at the Hudmel's, Puck finally understood that you were on Burt's blacklist only if you touched his family and Puck had no intention of ever being impolite with Carole or punch Finn again or go back at throwing Kurt into the dumpsters. Carole was like a mother and Puck knew you had to respect moms and Finn was still-more-or-less his best friend and Kurt was his boy and he'd be damned before he hurt anyone of them. So he stopped being afraid of Burt Hummel and started watching him being the father he always wish he had or was.
By the time Senior year rolls around, Puck has learned a lot from Burt about how to be a good man and provide for your family and have great kids and make them proud and when Shelby shows up again with Beth he does his damn best because now he has someone to look up to.
He sings to Beth and mixes strange stuff in bottles for her and plays with her and tries to braid her hair and tells her all about boys and how she better stay away from them until she's thirty eight. He makes the mistake of sleeping with Shelby thinking that if Shelby needed him then perhaps this time he won't be tossed aside as soon as he's not useful anymore. The plan doesn't really work and after a little lover a month he's back at being a father who can't be a dad.
He starts spending more time over at the Hudmel's pretending to be there to play with Finn and Sam or do homework with Kurt, but truth is that he's still trying to pick as much as he can from Burt. He watches Burt being an amazing husband for Carole and an even more awesome dad to Finn and Kurt and he starts taking mental notes about how he should behave if Shelby comes back and he has another chance with his daughter or about how he should behave if he ever figures out the true love thing and gets married.
Puck doesn't even notice when he starts behaving like Burt around other people. He catches Kurt looking at him with a perplexed expression every time he's giving Finn advices about Rachel and he gets why Kurt looks at him like that because only two years before he was ready to marry Quinn just because she was pregnant but he didn't make that mistake and he won't let Finn make it either.
He also doesn't notice when he starts wearing stuff he has seen Burt wearing, it's just that he's trying so much to be accepted by Burt, to learn from him, that he does almost everything with Mr. H on his mind. He doesn't skip classes because Burt wouldn't approve of Finn and Kurt doing that; he doesn't smoke weed anymore because that's also wrong; he talks about sleeping with every sort of girl but truth is that they all treat him as their friends (he doesn't even get upset when he takes the sorority to Sugar's Valentine's night and Blaine ends up dancing with them) and he doesn't even mind. He's still trying to figure out exactly what Kurt meant by true love because he's sure that's something Burt knows all about.
He's sitting in the Hudmel's living room a month after Regionals when Burt comes back home waves at him and then stops in his tracks.
"Hey, Mr. H."
"Is that my shirt?" Burt asks staring at the red and black checked shirt Puck is wearing.
Puck shakes his head and goes back to his homework wondering when Kurt is coming back down because now that they have a real Spanish teacher he doesn't understand anything anymore and Kurt has promised to help him out. "I bought it a few months ago."
Burt nods slowly frowning a little and makes a mental note to talk about this with Carole. He goes to hug Kurt when he sees his son coming downstairs and then leaves to get himself a beer.
Puck scoots closer to Kurt on the couch and tries his best to focus on their homework.
Puck and Kurt get together after Nationals at Finn and Rachel's wedding because they've been organizing it for months as the bride and groom's best friends and because they organized a flash mod together and a wedding has to be easier than that.
It turns out it's not but Kurt does almost everything and lets Puck choose the cake, the same cake they end up squashing when Kurt sees it and demands to know why Puck thought putting purple on a wedding cake was a good idea. And Puck just wants to shut Kurt up because they need to take the cake out and the guests are waiting and he really doesn't have time to tell Kurt he saw it on Ace of Cake and thought it was a cool cake.
He grabs Kurt's flying hands and kisses him and Kurt is surprised for a moment and just stands there frozen before he pulls back and looks confused at Puck. All Puck can think is that Kurt is really oblivious for being so clever because by now Puck is sure that at least every member of New Directions has caught him staring at Kurt.
He's about to say just that when Kurt grabs the lapels of the jacket of his suit and pulls him forward into a much more heated kiss and it's not really Puck's fault that he kinds of forgets where they are and he just kind of lifts Kurt on the table and on top of the cake. The worst thing is that Finn and Rachel come looking for them and they can't do anything but laugh because they're covered in cake and they were just caught making out and it all looks like a scene from a movie.
After the wedding things change because Puck is sort of Kurt's new boyfriend and when Burt sees him yet again wearing a shirt that it's the exact replica of one of Burt's, he stops Puck after dinner and has a talk with him.
"Son, what the hell is going on?"
"I'm kind of in love with your son, Mr. H. have been for a while and Kurt finally caught up so we are trying the dating thing and…"
"No, no I wasn't talking about that," Burt cuts him off shaking his head. "I was talking about the shirts. The one you're wearing right now it's exactly like the one Carole bought me two months ago."
"Oh." Frowning, Puck looks between himself and Burt starting to feel embarrassed. "I didn't notice." He sighs and looks up at the older man and apologies. "I'm sorry, Mr. H."
Noticing how serious Puck looks, Burt shakes his head and puts his hand on the boy's shoulder. "It's okay, I was just curious. No need to apologize."
"I really admire you, Mr. H," Puck says truthfully, his brow knitted together to convey his seriousness. "My father was a deadbeat and you're like the dad I wish I had. I didn't want to be creepy I'm just trying to learn."
Burt chuckles trying to ignore the fact that his eyes are becoming a little watery at finally understanding why Puck often looked at him or what was the matter with the shirts. "You're a good kid. I wouldn't let you come here or date Kurt otherwise." Adjusting his baseball cap and clearing his throat, he ads, "Just, now you're dating Kurt so it would be better if you didn't dress too much like me."
"Of course, Mr. H."
"Good." With another pat to Puck's shoulder, Burt sends him off to find Kurt so Puck can give him the good night before leaving and Burt makes a mental note to tell Kurt to be careful with Puckerman's heart.