The pair were recently filming the talent show when gypsy Gary Webb, 27, turned up to sing for them.
After he was voted through to the next round, Contostavlos, 22, showed the US singer how gypsy boys 'grab' girls, which was demonstrated on the Channel 4 show My Big Fat Gypsy Wedding.
Rowland, 30, asked her: 'When do you grab the girl?'
Contostavlos then replied: 'Everywhere. You grab the girl, then snog her face off.'
A source said to UK newspaper Daily Mirror: 'Tulisa was loving the fact there was a gypsy and was quizzing him with Louis [Walsh] for ages.'