Why Athena cursed medusa?

Athena cursed medusa because Medusa was a priestess at Athenas temple. Being a priestess for athena includes many things but the biggest one was remaining a virgin. However, medusa was veery beautiful and Posiden fell in love with her and wanted to have sex with her. She refused but he wouldn't take no for an answer and he raped her. Athena heard that Medusa was no longer a virgin and cursed her.