First up, I think my first gay couple, from the pre-randomization era, Bill and Ira (generation B spare and spouse):
Bill somehow had a gender preference on his own, and to this day I'm not sure why. He did have 10 nice points and his college Greek House did have a male cow mascot, so I have my suspicions though. In any case, he found Ira, who was perfect for him, and they were the sweetest couple. While digging, I also found their wedding picture.
I also have this servo-vampire pairing that'll probably hang around until the end of the alphabetacy (so 20+ generations), seeing that they're both immortal and involved in plot, George (the servo) and Count Pao.
Late generation B, there was a set of twins in the extended family, Barbara and Beatrice, who are both into ladies. Barbara married her sweetheart Tara (top), Beatrice and her partner Brenda (bottom) prefer to just live together.
Then there's of course the trio of Carl and his two ladies Audrey (left) and Veronica (middle).
Carl and Veronica have twins together, and Carl and Audrey have one son. All three consider the three kids as theirs. They're very close in age, Audrey and Veronica were pregnant at the same time.
A bonus picture of the trio, from Carl's cousin's wedding. (Oh, and on the foreground, I just realized the lady on the left is Claire, so Bill and Ira's adopted daughter, and on the right is Joy, the mother of the twins Barbara and Beatrice.)
While digging that last picture out, I realized that the cousin mentioned, Cyrus (my generation C spare) should also be in here. He and his wife Chris may seem ordinary enough, but I know better. Cyrus technically randomized bi, but through his life he's bolted for very, very few sims. He was pretty oblivious to Chris' flirting too, although when Chris came clear about her feelings, he happily went along with it. In my headcanon, he's probably either grey a or demi.
Finally, the youngest of the party. Aaron Davidson (from my BaCC) is my first sim to officially randomize ace. He's still a teenager, so we'll see where life takes him later on.