Carlisle takes that invitation, knowing well that Glacius likely saw the bleariness in his eyes as he promised to stay despite warnings both from Carlisle himself and the threat of what his abilities could do. Though he fears every day what could happen if his existence somehow taints his partner, bringing tragedy and misfortune upon them both, Carlisle cannot turn him away. It is far too late for that, and he is a selfish thing, so desperate for the connection they share that he'd do nearly anything to keep it. Glacius would, as well. He know that to be absolute truth.

Carlisle curls as close as he can to Glacius, his brow pressed to the underside of the alien's neck, arms resting against his chest. "I thought you would still be susceptible somehow. That is how I sent the other you away, after all... but his will must not have had the strength of yours. I'm... glad it didn't, in the end."

If the other Glacius had turned out to be the stronger of the two, they wouldn't be having this conversation, nor their coupling. In all honesty, Carlisle might not even be alive. How different would things be if he hadn't sent the other Glacius away that fateful day?