[ One day, Cairngorm will trust Lupin to not fumble anything and everything... That day is apparently not today, but maybe he can start changing their mind. He gingerly picks up the arm (once again noting how damn weird this is, but trying not to think about it) - which is heavy, but in comparison to their main body, feels light as a feather - and the brush before taking a seat next to them. The poor couch creaks under their combined weight, but it's fine. Probably. ]

... Do you really have so little faith in me? [ he comments ruefully, noting their cautious posture as he begins applying the resin. ] I know you don't really remember, but we've already come this far, haven't we? I'm not gonna break you.

[ normally, he'd make some cheesy comment about how the famous Arsène Lupin knows full well how to handle priceless treasures, but there's not really any point when A) Cairngorm doesn't even know his name and B) they always take his posturing as proof he's full of hot air, anyway. ]