Una's is a new one and I don't think it's in the wiki yet. I think you have to be a male (maybe with high feminity score too) and unlocked Dhaal. I got it after spamming her "sit on me" scene a bunch of times.
We're putting in a hint at the end of the regular content that you have to have found Dhaal first, because it's obvious players that are actively seeking it out are struggling to get it.