Meer Campbell: Relationships
Durandal and Meer: The Deception
The Chairman of the ZAFT council after Patrick Zala's demise, he's a very charismatic, devious and brilliant man who becomes the master of the politics in the SEED: Destiny universe. Despite not belonging to the military, Meer is one of his aids; he contacts and hires her as the doppleganger for the missing Lacus Clyne, intending to use her still-strong influence over the ZAFT people for his own purposes. Athrun warns Meer that she'll most likely become more of a puppet than anything in Durandal's hands, but Meer seems to be very much convinced that Gilbert means well and that he'll keep the peace. And if helping Durandal to keep the space peaceful and all means to impersonate someone else, then Meer will do so. Only much later, she'll start to doubt about his intentions. . .
Athrun and Meer: What Could Have Been
Athrun is the son of ex-ZAFT leader Patrick Zala, and Lacus' ex-fiancee. Meer thinks that Athrun is still engaged to Lacus (she never knew that Patrick broke the engagement off after Siegel Clyne's apparent treason), so she naturally goes all bubbly and chipper at the sight of the man. Nobody can exactly blame her for it: he's handsome, a good person, intelligent, a skilled pilot, and still a hero among many. She had a rather bizarre idea of how Lacus would act towards Athrun to cheer him up, though, which explains the famous bed scene and her fangirlish attitude when in his presence.
Athrun himself doesn't seem to love her romantically and is embarrassed by her advances, but this doesn't mean that he hates her. Oh, no. He does appreciate the fact that he owes her his life, and does care for her in a way: he does offer her to run away with him, then goes to her aid when she tells him through a note that she'll be killed (he knows it's a trap, yet says that even then he can't leave Meer alone with the enemy), and is emotionally crushed when she finally dies. In fact, he's the one who carries her lifeless body to the Archangel, in his very own arms.
Lacus and Meer: Pink Princess
Early on, Meer expresses her admiration for Lacus. She says everyone needs Lacus since she's graceful, beautiful, kind and strong. Meer used to be one of Lacus' fangirls, after all, and used to sing her songs until she was discovered. To Meer, Lacus is the mirror of all her inspiration and dreams, she's the person she wants to be... the one who's admired and loved not only because of her pretty self, but because she's the embodiment of strength and hope. Meer wants to have at least a part of Lacus' essence, the part that will make her desirable and loved - as well as able to work for a better world.
Lacus isn't exactly upset at the fact that Meer has taken her public place; in episode 46 she's nothing but kind to Meer, telling her to search for her own dreams, shielding her when they're under attack, and breaking down when Meer gets shot in her place and soon dies in her arms. Finally, in episode 47, Lacus takes Meer's death as seriously as Athrun, if not even more. As said before, Meer was there because people needed Lacus' strength and Lacus herself wasn't there for them, despite the good reasons she had to leave PLANT. Meer reminded Lacus of her place in the Destiny world, and gave her more motivation to finish the current war. Her expression in this pic says all; fans have commented that Lacus had never looked this upset and angry until then.