He hears it the moment he walks through the door, carrying the plastic bags of groceries in his hands that are nearly cutting off the circulation in his fingers. He barely gets the door unlocked when he hears the sound of Blaines guitar, and it sounds like its coming from upstairs in the music room. He assumes that Devon is in the room with him, most likely watching in fascination with his own little guitar that Blaine had bought him for his first birthday. Kurt smiles and heads to the kitchen, setting down the bags on the counter before beginning to put the groceries away. He nearly drops an apple, though, when he hears the sound of their son singing, or yelling rather, the lyrics to the Beatles song Blaine is currently playing.

He sets the groceries aside and begins to head up the stairs, because he just has to see this. He can hear Blaines voice, too, and he thinks that maybe the reason he has been singing this song every single day for about the past month with Devon in the room is because hes been trying to teach it to him. Kurt quietly peers into the room, not wanting to disturb their little jam session, and sees Blaine sitting on a stool, strumming his guitar, and Devon doing the same, only everything was much smaller with him. Kurt leans against the door frame and crosses his arms over his chest as he watches the two of them, smiling to himself. 

Blaine sings a few more lyrics, and Devon mumbles along with him, until he looks at the little boy with an expectant look, and he knows thats his cue.

"DON LET ME DOWN!"

Kurt has to cover his mouth with his hand to prevent himself from laughing, and Blaine grins so wide that the corners of his eyes start to crinkle in the most adorable way.

The song ends too soon for Kurts liking, but he figures he can always get them to put on another performance, and maybe he can even take a video, just so he can relive the experience later if he wants.

Kurt decides to make his presence known now, and steps into the room, causing Devon to look up at him, a large grin appearing on his face when he notices him. Blaine notices the look on his face, and he knows that it means Kurt is home. He turns his head around to see that his correct and the smile that appears on his face is identical to that of their sons.

"Hi, baby," Kurt greets Devon as he toddles over to him, crouching down to his level for a moment and lifting him up in a hug, pressing a kiss to his cheek as well as he giggles happily.

"Did you enjoy our performance?" Blaine asks as he stands up, setting his guitar to the side and walking over to the two of them and pressing a chaste kiss to Kurts lips.

"I did," Kurt answers with a nod of his head and a small smile on his face. "Is this why youve been singing this song to him every day for the past month?" he asks

His suspicions are confirmed when Blaine nods, a proud look on his face, and Kurt knows that he is excited to have taught their son his first song.

"Hes not even two yet and hes already a little rock star," Blaine muses, and he still has that stupid, giddy grin on his face that Kurt loves so much.

Kurt hums in amusement. "He learned from the best," he says, grinning back at his husband.

The proud look on Blaines face grows, and Kurt falls just a little bit more in love with him in that moment.

"I think I might video it next time and upload it to YouTube. Maybe well become internet famous."

Kurt chuckles until he sees the look on Blaines face and realizes that he is totally serious.

"Blaine-"

"We totally could."

"I guess, but-"

"Please?"

Blaine knows that Kurt isnt completely fond of the idea of exposing their child to the world, but even still he gives him his best puppy-dog eyes, because he knows he can never resist.

Kurt stares at him for a moment until his finally gives in, because its just one video, and how many people would really watch it?

---

Blaine ends up going through with making and uploading the video and Kurt doesnt discover it until three days later when his dad of all people mentions it to him and it already has over 500,000 views.

"I told you hes a little rock star," Blaine tells him.

But Kurt already knew that.