Billie watched with fury last night (20 January) as Sam found out that she is up for eviction following nominations from both journalist Liz and comedian Jim Davidson.
Billie, who is expecting her first baby with boyfriend Greg Shepherd, jumped straight onto Twitter and blasted the pair - but particularly Liz - for choosing her sister.
The star, who is slightly older than Sam, ranted: "I'm so annoyed with Liz's reason to nominate @SamanthaFaiers!
"It was alright when she was wearing Sam's dress and having her hair & make up done by her!! Pathetic reasons!! @SamanthaFaiers has made the most effort with her!!! #CBB."
Alongside an emojicon of a fist, Billie added: "And as for Jim..."
Following Sam's nominations, the housemates - excluding Jim and Liz - decided they had picked her for "tactical" reasons.
Linda Nolan was very quick to jump to Sam's defence. Noting this, Billie said: "Love how Linda and @SamanthaFaiers always stick together..."
Sam faces the chop alongside Jim and Liz in tomorrow night's eviction show.
Do you think Sam is safe? Tell us below, as the best comment from across the website each week wins £50!