Is it possible for Jon to have a little, just a little, crush on Sansa? In my opinion, the way he looks at her is not...how a brother looks at his sister. I mean, 3 years have gone by, Sansa is the only family member he has right now. But, their interactions are not really brother-sister. Maybe on Sansa's part they are, but Jon...Sansa has also grown very much as a person, she has become a gorgeous girl, he likes redheads, so who the hell knows?
I’m not going to offer false hopes re: how things could go in canon (because now more than ever I don’t see anything romantic happening between them either books or show wise) so please don’t take my answer that way… but in all honesty, this reading makes A LOT of sense to me. I’d be surprised if Jon isn’t at least a little bit ~confused~ about Sansa right now. She burst into his life, beautiful and vulnerable but also icy and strong-willed and inaccessible again, and I dare ANY young man not to find that mix fascinating. She’s completely different from the girl he used to know, and at the same time she looks and act so much like Catelyn, the woman who used to hold his whole life in her fist when he was a boy. We see how Petyr projects his unresolved feelings about Cat on Sansa, but what if Jon does too, to a smaller extent? Of course Jon’s feelings about Catelyn are very different. He was terrified of her, but also craved her attention and envied the love she granted his trueborn siblings, as she was the only mother figure available to him. It’s not unrealistic if he feels a degree of attraction mixed up with conflict and emotional distress for Sansa, who has now fully grown into her role as “lady Stark”.
Their interactions in the show make much more sense if you see them in this perspective. There’s unresolved tension about Jon’s bastardy, which both of them still feel acutely despite Sansa’s claim that it no longer matters; there’s Sansa watching her mother’s worst fears of Jon “stealing” her children’s birthright become reality, knowing that she partially contributed to that; there’s Jon sort of walking on eggshells around Sansa, acting awkwardly, quietly observing her when she doesn’t notice, studying her. She’s clearly not an easy person to be around, not only for the personal relationship they used to have (or didn’t), but for the social role she now embodies, a role Jon learned to be wary and lowkey afraid of since he was little.
And yeah, Jon has an ongoing narrative of being paired up with redheads, and Sansa… Sansa might be the one who closes the circle (because c’mon, who originated it if not Catelyn).
And tbh I wonder how their interactions could have been if Jon had learned his parentage before reuniting with Sansa. I’m curious to see how the whole thing happens in the books, timing-wise especially.