Athos smiled a bit at the huff, fingers fiddling with the bottom of his wine glass, though his eyes registered surprise when Aramis bent down on one knee, and he blinked, shifting a bit. He honestly had not been expecting this and he was not sure what to do-not sure if this was coming from their talk of before, that Aramis was doing this to prove something or because he actually wanted to, not sure if this was a gesture of love or of a stubborn old man making a point. However, looking into the man's eyes, Athos couldn't believe the man didn't love him. For all the flirting he did, for all the infuriatingly frustrating moments they shared, Athos was certain Aramis loved him.
It was a long pause as Athos went over all this, and his eyes remained on Aramis', his face not showing anything but contemplation before he slowly inclined his head, "Yes, Aramis. I will marry you."