"Please tell me that you won't leave without telling him." Aramis's brows draw together in consternation. "Constance."

He sees what she wants of him: to keep d'Artagnan from doing something stupid, just as Porthos as been tasked for him. "Your beloved is hard-headed," he reminds her. "I will do my best, but when he wishes to do something .... "

It is a reasoning that actually might serve both Aramis and d'Artagnan in this situation. Not that they would go against Constance directly ....