The Irish music mogul today told how he walked in a nude Tulisa in her dressing room at the weekend.
Describing it was the biggest shock of the series so far, Louis laughed: "Ha! Walking in on Tulisa with no clothes on. I sauntered into her dressing room and she was totally naked.
"That gave me quite a shock! She looks great though, it has to be said."
Speaking about the N-Dubz star, Louis gushed: "I think she’s in love. I can tell - she looks really happy and is letting me get away with murder on the show! I enjoy winding her up by calling her a WAG. It’s such a shame to have lost Ella but Tulisa has lots going on in her career with her album and so forth. She’s one busy bee!"
Talking of love, Louis said he hoped his boys in Union J would get with "non celebrity" girlfriends.
In an interview with the official X Factor website this evening, he said: " I’d like to see them date non-celebrities.
"Some ‘real’ girls who’ll treat them well and help keep them grounded. They’re such a pleasure to work with - they’re good guys."
The X Factor 2012 continues this weekend on ITV1 and ITV1HD with the final four acts singing songs that they hope will get them into the final.
On Sunday's results show, one more act get the axe and there will be performances from Pink and Tulisa.