Envy didn't make friends where he went. He made enemies and he made victims. Family was family but even then, how thick did blood between brethren go? He was amused by them. He and Pride sometimes had a pack about them. If the Excesses could team up like the musketeers or some shit, why couldn't the rest of them do the same? The Excesses were not special by any means. Just assholes.
If Sloth kept herself like this he could get used to it. Sloth might be doped up on coke and depression but he was hung up on misery and misery was the best company. Sloth could provide that. Envy was a psychopath, psychopath's got bored and she had sparked a little interest if just because Greed had said no. There was still some powder left in his hand even as Sloth tried to avoid the blood. He put the knife away in his back pocket so he could finger the coke against his lips. Now what would her move be? He was curious.