Just thought I would add that it is factually canon that they go to each each other’s rooms at night even in the bunker.
Sam is unbelievably pissed at Dean after Gadreel. He agrees to live with Dean, be hunting partners, share half their DNA, etc etc etc, but not to being “Brothers” and Dean understands exactly what he means.
Then after they rescue Kevin’s ghost from being trapped in the bunker, Kevin tells Sam to get over his anger at Dean for the whole Gadreel thing. (Keep in mind he’s been watching them as a ghost since Gadreel killed him!) Kevin leaves and Dean tries to initiate a hangout … and Sam rejects him hard.
Sam walks to his own bedroom and his hand practically shakes on the door as he forces himself to go to his own bed instead of to Dean’s room. Dean, meanwhile, goes to his room and puts on his headphones and tries extremely hard to cope with the fact that Sam’s not coming to his room tonight
Once Eileen is back in Sam’s life, Dean has a very hard time coping. He drinks a lot, and you see the beers stacking up above his head as he tries to handle being alone in his room.
He goes and finds Sam and Eileen and they’ve made breakfast, including actual meat which Sam has recently been refusing. It’s a sign Sam is much more well emotionally and mentally. Dean feels left out (and also hurt that Sam will eat bacon when Eileen makes it but he won’t eat bacon when Dean makes it). Dean had had to trick him into putting his meat in his mouth and made weird sexual jokes about it that annoyed Sam (yes Dean announced that he’s the Meat Man, despite Sam’s protests) but here he is happily eating Eileen’s meat.
Dean tries to be good about Eileen, he tries really hard, but it burns. He tries to encourage Sam “practicing sign language” but he’s walking around with a gaping hole in his chest. When he hears that Sam and Eileen have an “arrangement” that isn’t as serious, it’s an enormous relief to Dean and you can see it in his eyes.
At one point, he jokingly-not-jokingly tells Sam to put a sock on his door so he knows when Eileen is in there, so he knows if he can come by at night. But Sam doesn’t think it’s funny. He doesn’t want Dean coming to room in the middle of the night right now whether or not Eileen is there and whether or not he and Eileen only have an arrangement. He silently rejects the sock idea.
IN CONCLUSION: This is all directly canon. They are in each other’s rooms at night and you can tell because something is wrong between them when they aren’t.
(Off topic but …. By the way, this is one reason why I reject the idea that Dean doesn’t ever let Sam say no. We see Sam say no on camera. Dean agrees to let Sam live with him even if they aren’t currently BrothersTM. Yes, he tries to trick Sam into eating bacon in part because his feelings are hurt and because he can’t respect Sam’s autonomy and right to choose vegan or turkey bacon or whatever. But Dean’s still trying to get consent, still suggesting hangouts and not forcing them, still jokingly and with semi-plausible deniability trying to figure out what he’s allowed and not allowed to do, trying to see what’s permissible in the most eyerolly way known to man. He probably becomes intolerable to live with until Sam’s back where he wants him, but no he doesn’t violently rape Sam. He’s a complete disaster but not evil come on.)