There's no love lost between these two.
In the latest spat between the two volatile housemates, Perez Hilton has accused Katie Hopkins of being "homophobic" after she told the blogger to "man up".
The incident flared during a task - a debate which asked the housemates to tackle 'key dynamics' of the house.
Katie was berating Hilton when she told him "If you have a problem, take it like a man".
Perez responded with "please stop telling me to take it like a man. That's homophobic".
Other housemates were not sympathetic to his claim, with some exclaiming "oh my god" and others adding "Stop reaching".
Katie exploded; "Do not accuse me of homophobia!"
"Of all the things I am, that is not something (I am)".
When the debate calmed slightly, Katie instructed "do not try that again, Perez, that's lame".
Tensions flared again as Perez began blowing kisses to Katie in an attempt to wind her up.
"Do not taunt people. You are revolting".
"Blow a kiss at me again and I will chuck this water at your head".
Housemates attempted to calm the situation, telling a frustrated Katie "Don't rise to him. Not worth it".
"This is what I have to put up. Why is it always me? I'm not allowed to rise to it - he's always allowed to do this. Why don't you level it at him?"
This series of Celebrity Big Brother, airing on Channel 5, has seen perhaps more controversy than any other.
Baywatch star Jeremy Jackson was removed from the house following a "sexual incident" where he was seen "opened model Chloe Goodman’s dressing gown and touched her breast leaving her deeply upset".
Alexander O'Neal was also removed from the house following the use of a homophobic slur against blogger Perez Hilton.
Perez had been taunting O'Neal, blowing him kisses when O'Neal used the slur, saying “I know what you want but you’re not going to get it ... you’re going to sit there with that silly ass f****t look on your face.”
Former Coronation Street star Ken Morley was also removed for the show for using offensive language, including "repeated use" of the word 'negro'.
Over 250 complaints have been received by UK TV watchdog Ofcom about the show.
UK TV watchdog Ofcom is assessing hundreds of complaints about Celebrity Big Brother after former Coronation Street star Ken Morley was removed from the show and another contestant was cautioned by police.