Why when girls have sex they get called a slut but the guys don't

Bri

Three years ago when I was in middle school I have sex with a 21 year old and the whole school found out i got called a slut,a cunt and a bitch and guys just wanted to date me just for sex and when I didn't give them sex they just broke up with me!!! This 21-year-old just got damn you top that congrats man I'm proud of you and all that shit but he did not get grief about having sex with a under aged girl but till this day I still get called a slut, and other names 😤😡