While he didn't want to keep their mother from seeing Sam, Dean was taking precautions with the situation. He already knew that their mother still harbored guilt over the situation and he didn't want Sam to callously slip and say something he normally wouldn't. Although, he wasn't sure if he could keep things that way for long. Still, it was better that he assess the situation before going forward with anything else.
"Awesome, grab a seat and I'll be right back." He motioned for Sam to take a seat at any of the tables and he made his way to the kitchen to grab two beers from the fridge and returned quickly. "No, uh, Adam lives here too and I was planning on inviting the weird kid who looks like me." Dean set a bottle down in front of Sam and took a seat across from him.
"This place has plenty of room, though, and all of your stuff is- well, the stuff that belongs to future you, I guess? It's here. Clothes and all should probably fit, though I think you might have gained some muscle over the years and maybe the arms will be a little tight in your shirts? You're welcome to check it out, of course."