Porthos is so used to this, but he's not used to it happening while Athos is beneath him, making him feel as if he's been bracketed with such perfection that makes him writhe and moan and hiss with it, panting downwards as he leans into a hard kiss, thrusting his arse back to push Aramis deeper inside him, a selfish and sudden act that he can't imagine Aramis being upset with.