Sloth wasn't looking at his belly, just helped him undo his jeans and pulled them off so she could straddle his lap and kiss him again. It was awkward and a bit uncomfortable, but Sloth felt glory at capturing a bit of something of Greed's. Greed could never do what she could, not really. Maybe he wouldn't notice her swiping until it was too late, and she'd consumed all Digger's willpower.