The Love Island presenter won the BBC dance show in 2014 with professional dancer Pasha Kovalev but fell victim to the infamous Strictly curse when she split from her music manager boyfriend Jack Street just before the final.
Flack, 40, reflected on her win on spinoff show It Takes Two, saying: “It's never just about one person. Being in a Strictly couple is like being in a relationship.You have to have all those same traits. It's a partnership.”
She added to host Rylan Clark-Neal: “Let me finish that before it goes anywhere else. You have the trust, honest, communication. Get rid of the romantic bit. You don’t do it on your own.
“I would never have been able to do it without Pasha. If you get that right partner it works.”
Flack has been dating Street for 18 months when he dumped her after she made it to the Strictly semi-final.
Writing in her book Storm In A C Cup, she said of the breakup: “He had seen me come back from losing Xtra Factor. Now I was finally finding my feet. I felt that he could at least have waited three weeks... and I wept.”
Flack is currently dating former tennis player Lewis Burton, 27.
Kovalev, 39, is now married to Countdown presenter Rachel Riley, 33, his partner on Strictly in 2013. They are expecting their first child together, due any day.
Since Strictly Come Dancing began in 2004 numerous celebrities have fallen victim to the curse, with their relationships breaking down as a result of taking part on the show.
After the very first series, newsreader Natasha Kaplinsky split from her long-term partner Mike Barnard and her dance partner Brendan Cole ended his engagement to Camilla Dallerup.
Other victims of the curse include singer Louise Redknapp, rugby player Ben Cohen and dancers Katya and Neil Jones.
Strictly has sparked numerous romances including Flavia Cacace and actor Jimi Mistry, Pussycat Doll Ashley Roberts and Giovanni Pernice, and last year’s winners, TV presenter Stacey Dooley and her partner Kevin Clifton.