The first time they kissed it was in full Summer, when they were almost ten.
Robb had bet with Theon that he'd kissed ten people in a day.
He managed to convince nine servants, but he couldn't find a tenth. It was a few minutes to the deadline when he found Jon in a hallway near the kitchens.
-Sorry for this.- he said before pressing his lips against Jon's.
Jon didn't say anything while Robb was running away, he just stood still listening to his brother's steps echoing in the hallway.
Robb lost the bet anyway because he was too ashamed to tell Theon he kissed Jon.
Later, while he was running around the godswood for penance, he wondered about why he was ashamed.
Obviously, he tried to convince himself, because Jon was a boy and boys aren't meant to kiss boys.
The truth was that Jon's lips were the sweetest and softest out of ten, and the only ones he wanted to kiss again, but he'd never admit it even to himself.
A few weeks later it was Jon that untied the tangle of Robb's doubts.
-Theon told me you lost the bet. Actually, he told everyone. Wasn't I helpful?- asked forcing himself not to grin.
Robb got red like the Lannister coat of arms, but there was no trace of a lion in him.
-I shouldn't have kissed you. Pretend that I didn't.- he said, but he wasn't sure at all of his words.
-Not for me. And neither for you, I can tell. Anyway, nobody has got to know but us.- he was definitely grinning.
Robb opened his mouth to ask Jon what he meant, but Jon caught his words on his lips, and his breath inside him.
Robb got ever more red than before and extremely warm.
When Jon parted from him, Robb was panting.
And wanting more.
The wide, bright smile that curved Jon's lips meant that he knew it was only the first of a long, long row.