Alex was joined by Oritsé's bandmate JB Gill to support the couple as they showed off their moves on ITV's celebrity dance contest on Saturday night (7 September).
Alex, who looked stunning in a red Dolce & Gabbana mini dress, cheered on the couple from the studio audience with JB.
Oritsé and AJ, who made it through to next week, received rave reviews after putting on a stunning performance dancing to Salsa in the second week of the competition.
Posting a backstage group photo alongside former Westlife member and Stepping Out contestant Brian McFadden, Alex said: "Well done @oritse and AJ! Keep up the amazing work! S/out to @BrianMcFadden - lovely seeing you too !! Xx #steppingout."
And it appears that Alex was not the only one to give praise, as JB said the couple had made him "proud".
He tweeted: "Sick show!! @oritse through to next week. Did me proud today with @AJAzari #gwan good luck this week!"
Rochelle Humes, who watched the peformance from the comfort of her home, compared Oritsé to international music sensation Usher.
She said: "Wow @Oritse @AJAzari that was like Usher and Beyoncé, loved it. Can't wait to come and watch xx."
Meanwhile, Union J singer Josh Cuthbert, said: "@Oritse you smashed it on Saturday night bro!!!!! You've got the moves boy!"
Alex was also visibly chuffed to see someone else at the studios - Stepping Out presenter, Davina McCall.
The two embraced each other with hugs as they caught up backstage.
Posting a collage to Instagram, Alex said: "So lovely seeing Davina last night! Such a special lady ! #steppingout."
Watch Oritsé and AJ perform their salsa below: