I doubt that, by the time of the Catalaunian Plains, he still considered the Huns as friends. He was acting as general of the Roman forces and I especially doubt that he would express any recognition for the Huns in front of his army.
Although he definately still had a strong Relationship with the Huns, Attila was to young to have known Aetius growing up. Aetius had Huns in his army, the Huns were not one united people, not all of them liked Attila. Same reason you have multiple Visigothic Leaders, records of 3 Kings of the Ostorgoths (of which Valamir was higher in Rankin Attila's Court) and 2 leaders of Alanic Foederati serving Aetius.