The singer - also known as Clapz Shizzayne - allegedly got together with an unknown female member of one of the groups after their first day of filming.
Contestants had been treated to a night out in Liverpool by show producers, before the pair went back together at their hotel, reports The Sun.
However, the girl asked Nti to keep her identity a secret.
Nti said: "I didn't really rehearse because I had a friend come round.
"It wasn't what I expected it to be but she was decent, so I just kissed her and it developed into... you know what I'm saying.
"I promised I wouldn't say the name. She was really begging me, 'Please don't tell anyone. I don't want my parents to know'."
The singer was told to be on his best behaviour before heading out into Liverpool.
An insider said: "All the contestants are told to be professional and focus on their audition but producers can't stop things like this happening. The fact he didn't have enough time to rehearse caused problems."
The X Factor continues this weekend with a double bill of Boot Camp episodes on Saturday and Sunday.