Your sister has invited her 2 friends Amy and Mia to a sleepover. Eventually she realizes that she doesn't not have enough space for them in her room. So she decides they will sleep with you in your bed.

She comes into your room with Amy and Mia. Amy and Mia are only in bra and panties I guess that's how they like to sleep. Your sister quickly explains to you what's happening. She sees u don't like the idea but doesn't care and storms out