You see someone that you rejected and do not want to be with, with another person, and yet you still feel bad and like you were the rejected one. What IS that?

Literally, I know that I have 0 desire to be with this person - I find them pretty boring and they have the smallest penis I have ever seen and some weird commitment issues, and I also like the girl they were with and think she would be a much more compatible person for him and bless them both.

But still... I feel mildly bad even though it’s something I don’t want. :’( Please just tell me everyone feels like this!