Stephanie Davis and Jeremy McConnell got intimate beneath the covers in the Celebrity Big Brother house, although it was unclear whether the pair had full sexual intercourse.
In footage screened on the Channel 5 show, the two contestants shared a bed and made so much noise that other housemates were forced to leave the room.
As they lay in bed together, Davis first said: "It's our last night in here."
McConnell told her: "I'd never do anything like that in here."
But the two continued to move under the covers together, with Davis complaining that she was not wearing nice underwear. She also let out a cry.
Later, she worried: "Do you think I was loud? What if they show me doing that on TV?"
Gemma Collins and Danniella Westbrook went to the kitchen after becoming fed up with "shenanigans" in the bedroom.
Westbrook said: "All I can hear is them getting it on, I'm so embarrassed. I don't want to take my fingers out of me ears.
"I couldn't do it, could you - on the telly?
"Don't take her foot off the gas, does she? It's one thing after another. It's just a real shame. It's just a level of disrespect for everyone in that room."
The Only Way Is Essex star Collins replied: "I cannot believe it."
In bed, Davis told McConnell: "I think I'm falling really badly in love with you Jez."
Either she or McConnell will be evicted in Friday night's show, with US reality star Tiffany Pollard - who was also nominated - having been saved from eviction by viewers.
For the task, the house was filled with telephones. The contestants had to answer all phone calls and work out who is on the other end of the line - with callers including Darren Day's wife, I'm A Celebrity champion Vicky Pattison, and former housemate Christopher Maloney.
Westbrook said: "I might sleep in the lounge just to man the phones. I can't sleep with all that shenanigans."
Pollard said: "That makes me uncomfortable now. It wasn't bothering me until now. You know what it is, it's the sounds of kissing."
After a heated argument, Davis is not currently speaking to Westbrook, branding her an "absolute carrot".
The dispute centred on Davis's behaviour in the house and her developing romance with former Mr Ireland McConnell, as she is in a relationship with model Sam Reece.
Westbrook previously told her: "You'll never work again off the back of this show."
But in the diary room, she insisted the feeling was not mutual.
She said: "I'm upset about the situation with Steph. I'm gutted, but I'm alright with it, because I know what it's like to feel under attack and vulnerable so I don't hate her or anything. I don't feel any dislike towards her; I love her to bits still."
Pollard, McConnell and Davis are all up for eviction during Friday's show.
In the diary room, Pollard declared her intentions towards McConnell if Davis is the one to leave the house.
Pollard and McConnell have already shared a kiss during a game of truth or dare, upsetting Davis.
She said: "If Steph were to go home, I would have to say of course there's going to be more opportunities to have fun with this beautiful young boy.
"If I can't take it any more, something is going to happen in this house. I'm definitely in the mood."