Jem Palmer's exit prompted Big Brother to decide that all housemates who received any nominations on Monday would face the public vote.
Aaron had already been put up for nomination alongside Jem after he received the majority of votes on Monday.
Tom O'Connell, Alex Rose and Louise Cliffe are safe for another week of the reality show.
After a number of threats, Jem finally walked out of the house this afternoon despite protests from fellow housemates.
Big Brother's seventh eviction night will air this Friday at 9pm on Channel 5.