Roman
Roman isn't a big drinker, he never has been. He's always been responsible, knowing that you and Dean would drink so much that you wouldn't be able to drive home. When you do drink a little too much, whether it's at a bar, or just at home for a fun night together, he's always the one to make sure you get to bed safe. He's always enjoyed you when you were drunk, you admitted to things that you wouldn't normally admit to, you laughed a lot more, and the effects of the world didn't seem to be there. Roman has always looked out for you, for as long as he has known you, he's felt this responsibility to watch out for you, to take care of you, just the same as Dean and Seth have for him. When he sees you're tired or have had enough, he'll carry you off to his room, leaving you in your clothes. He'll watch over you the whole night, in fear that you come down sick with something like alcohol poisoning.
Dean
Dean's alcohol tolerance is much higher than yours and he knows that. When you suggest that you all take the night off and hit a bar, he doesn't disagree. He knows when you've had a little too much to drink. Your words slur slightly, not something that is noticeable, especially if you're not looking for it. You can't walk straight, and you think almost everything is funny. He makes sure that you are safe the whole night. He sends off drunk men, telling them that you are his, even if it isn't true. He carries you through the hotel to your room, trying his best to avoid any people who might rat on you and get you in trouble with Stephanie and Hunter. He takes off your boots and tucks you into bed. Then he strips off his clothes and climbs in next to you so he can make sure you're okay for the rest of the night. He places a kiss to your forehead before sleep consumes him.
Seth
It takes a hell of a lot to get Seth drunk. When you both drink together, you're smashed before he can even feel the effects of the alcohol. You watch him throw back, shot after shot, waiting for the alcohol to consume him, but it never does. He sits there and watches the confusion rise on your face. He can sense the alcohol in your system, and the pain it causes to your head as the effects wear off. When you have finally given up on getting him drunk, he gladly puts away the alcohol and fetches you some Advil, relieving any pain that the alcohol will cause you. He takes you outside to get some fresh air, wrapping his arms around you while you look up at the night sky. It isn't long before sleep consumes you.