SOLVED. YA Mystery. Four teens are invited to a dinner party by the sister of the kid they murdered (by accident at a party). [s]

[pvt]

So I read this book in 2019, and these teen high schoolers killed a kid by accident at a party (i think), and the sister of the victim called them a year later to this dinner party, where she slowly kills them off. I'm pretty sure she was bald too, because these kids poured chemicals in her shampoo thinking it was her brother's. At the end, I think there's a fire.

[Rainbowheart]

Ten?

The Invitation?

Halloween Party?

[El]

I know this! 99% sure it's This Lie Will Kill You
has the chemicals in shampoo, dinner party and sister

[pvt]

YES! THIS IS IT!! thank you so much i have been looking for ages.