It's always fun to use context clues to unravel inexplicit details of relationships between characters. For instance, Martian Manhunter appears to be one of the few super-heroes Green Arrow truly admires, but Ollie's kneejerk opining and swagger seems to have kept their relationship tepid. Black Canary is a sweetheart, but runs in separate circles. Manhunter's relations with Green Lantern Corpsmen have always been strained, but there is mutual respect with all the Flashes. I don't believe Hawkman ever forgave the Alien Atlas for sucker punching him back in the '70s, and although they rely on one another outside of teams, Katar is unceasingly antagonistic. The Atom, Zatanna and Elongated Man are all agreeable.
J'Onn is clearly coziest with the DC Trinity, but also has a complex connection with Aquaman. Mutual tragedy and alienation seem to draw J'Onn and Arthur to one another, but Aquaman can be very abusive and fearful of intimacy, about which J'Onn is unusually tolerant. Conversely, Martian Manhunter and Firestorm have always been mildly antagonistic and distrustful of one another, with J'Onzz handing down lectures, and Ronnie getting fresh.
Recently, The Irredeemable Shag's Firestorm Fan and Rob Kelly's The Aquaman Shrine connected their respective dots, based on conversations that took place in Justice League of America #193 & 203. Shag has a gift for drawing exclusive archival material out of creators, and netted excerpts from an original Gerry Conway script that, as he put it, "ended up on Editor Len Wein’s cutting room floor." The following is taken from Shag's excerpt of an early draft for June 1982's Justice League of America #203. The scene involves the Sea King taking the Nuclear out into open waters as part of a training exercise...
Page 2, Panel 1
Firestorm thought balloon: I wouldn’t even be here if Martian Manhunter hadn’t made me promise to be nice to Aquaman.* Apparently, Martian Green-Genes has a soft spot for the Sea King.
* NOTE: Martian Manhunter and Firestorm met recently in JLA #200 – Editor Len
That's the sum total of Martian Manhunter's involvement, which bolsters my theory about his friendship with Aquaman, but might leave you hungry for more details. Visit Firestorm Fan for the full skinny on the excised portion, of which the above was only a snippet, and visit The Aquaman Shrine for his side of the story.