[Porthos would likely be able to sense anyone approaching faster than Aramis could, but that doesn't keep him from keeping an eye out anyway, knowing even as much as their position at the moment is dangerous enough.]
[Of course, that only... works even better for him. Slow and careful as the drinking is, gentle as Porthos's hold is, his heart is still racing, he's still shivering against him, his breathing quicker just from this.]