I was having dinner with my sister and she said some of my old highschool "friends" reached out to her to invite me to a highschool reunion because they couldn't find me on the FB. I told her I'm not interested and she said if you're not going then I'm going because some of those guys are really muscular (some of them are pro athetles)

I understand this shouldn't bother me because we're both adults (im 28, she's 26) but i still feel annoyed that she wants to have sex with the people who used to beat me up in school, am I right? Should I say something?