Aquaman and Mera is one of the main relationships within DC Universe and it's expanded franchise. Originally sent out to kill Arthur, Mera fell in love with him and they've been together ever since. Married and in love, meets and Arthur are one of the ultimate power couple.
It was one of the main and iconic pairings within DC universe History, alongside Iris and Barry, Lois and Clark, poison ivy and Harley, Dick and Barbara, etc.