Disclaimer: Harry Potter isn't mine.
Severus' POV
You never expected that when you answered the door that evening that it could be anyone but one of your Slytherins, seeking help, or, God forbid, advice. Instead, it was Lupin, with an odd, nervous smile on his face. He slipped past you into the room, and somehow persuaded you to let him stay. You offered him a drink, and then ask him to come back for a game of chess. You'd never realized that actual conversation with a Gryffindor was possible before, and you're grateful it is. He's the only person since you started working here to even try, and the now frequent companionship highlights the previously ignored loneliness. Not being isolated was deeply unfamiliar at first; there was never a time you hadn't been before this. Voluntary physical contact is new as well. He puts a hand on your knee as he talks, and leans over your shoulder while you brew potions. You can't seem to put any trust into this lasting, though. Happiness never does.