YOU SAID:

I’m at a sleepover w/ my bestie right now :)

INTO JAPANESE

今、親友とお泊り会中です :)

BACK INTO ENGLISH

I'm currently having a sleepover with my best friend :)

INTO JAPANESE

私は今、親友とお泊り会をしています:)

BACK INTO ENGLISH

I'm having a slumber party with my best friend right now :)

INTO JAPANESE

今、親友とパジャマパーティーをしています:)

BACK INTO ENGLISH

I'm having a slumber party with my best friend right now :)