[ He doesn't know the full weight, no, but he has a sense for it. He's seen how ready they are to hurt themselves all the time. Even if they can be put back together -- Lupin knows them well enough to guess that it's not all practicality. Cairngorm has made it clear in the past that they take promises seriously. He just has to have faith they'll take this one to heart, too.

For now, they're safe. They're getting better, if what they say is true. And, so far, they're still the jewel he fell in love with. That's enough for him. With their grip on his wrists, his range of movement is a little limited, but he tries to stand back up again - though he won't pull away from their hands, merely letting his own slip back into them as he moves to sit beside Cairngorm instead. ]

Thank you. [ his response is gentle and honest. This, too, is an expression of how much they've opened up to him, how much they're willing to trust him with, and it doesn't escape him. ] Then I'll promise you that I'll be here as long as you'll have me.

[ as long as he can make it last - he thinks again of how he'd asked them to come with him, but the thought is dismissed quickly. That's the last thing they need to be contemplating now. ]

... This fellow you saw in the lake. You're sure he was telling the truth? I've never once suspected there was anything wrong with you.

[ maybe his affections clouded his sight, but Lupin likes to think his senses are more keen than that. Then again, Cairngorm isn't even human. ]