Aramis and Porthos

Though close with all the Musketeers, Porthos and Aramis consider each other best friends. Meeting under unknown circumstances, they probably met each other when they joined the Regiment. He and Porthos worked together with D'Artagnan to prove that Athos was accused of murder. Aramis was highly concerned for his best friend when Porthos was nearly fatally injured by a group of bandits and made his healing his top priority. Aramis was also confident that Porthos was not a person capable of murdering a person, even manhandling D'Artagnan when saying Porthos probably did do it, showing that Aramis doesn't like it when even a friend accuses Porthos of something he didn't do it. In the same episode, Aramis killed Porthos' friend Charon but no animosity formed between the two, as Aramis was protecting Porthos.

However, despite their closeness, Aramis did not tell Porthos of his romantic relationship with the Queen and showed concern for Porthos when he and the other Musketeers thought he was in danger in the presence of his father. Porthos remained unaware of Aramis' brief relationship with Queen Anne until part one of the series two finale, where Porthos expressed anger that Aramis slept with the queen and not telling them about it.