Kurt had always loved Lazy Sunday. Back when he and Blaine were dating in high school and Burt would let Blaine sleep over the previous evening, Kurt would join Blaine on the couch in the morning, and later stay in bed with him, and cuddle in front of a movie, only separating to fetch some food or for bathroom breaks and inevitably around 6 when Blaine's mom called to remind them that he had shool the next morning and that the drive back to Westerville was long.
Later, when Kurt moved to New York, they would Skype on Saturdays, watching movies or trashy reality TV, and fall asleep, only waking the next morning to the sound of one or the other waking up. After their breakup, Santana and Rachel had taken over the Lazy Sunday tradition, first squishing him into the couch and feeding him cookies as he sobbed, or listening as he went on and on about every single flaw Blaine had. Slowly, as they got back on the track to being friends, he would spend every other Sunday texting him, while the rest of the time he would just spend time with Adam, never getting comfortable enough to stay in his pajamas when he was over.
After Mr. Shuester's failure of a wedding, and the Horny Hotel Mishap, as Kurt liked to call it, he decided to go back to spending his Sundays alone, just like he used to do before Blaine.
It quickly got tiring, and Kurt soon found himself yearning for Blaine's presence. That's why the first thing he did when Blaine asked him out again, was invite him to his place the following Sunday, for a well deserved day of lazy rediscovering of the other. A week later, as Blaine proposed, Kurt felt immense regret at not getting to spend one more Sunday with his now fiancé.
But now, settled in their bed, in their brand new appartment after moving more furniture than they thought they should own, Kurt's finger throbbing due to a splinter, Blaine smelling of sweat and Sam snoring on the couch, Kurt feels more whole than he ever has.