The 34-year-old professional wrestler and the 'Blockers' star were due to tie the knot in May but cancelled their engagement just weeks before their big day.
And on Wednesday (25.07.18) the sisters caused the audience on 'The Tonight Show Starring Jimmy Fallon' to groan and grunt after revealing that they never had to experience the heartache that goes with ending a relationship when they were teenagers, because they'd do it for one another without their boyfriends ever knowing.
Nikki confessed: ''Well, when we were young, we would break up with boyfriends for each other.''
And her sibling Brie - who is also a WWE Superstar - replied: ''We never had to go through like the emotions of a breakup because I was like, 'You wanna dump the guy, cool.' ''
Referring to her relationship with the 'Blockers' star, Nikki then quipped ''Where were you a few months ago?''
The 'Total Bellas' star recently admitted she felt she and John had ''grown apart'' shortly before they were due to get married.
In a clip for Nikki's reality show 'Total Bellas' - which was filmed before their split - the star admitted she doesn't feel as close to John as she used to.
Speaking to the camera, she revealed: ''I feel like I'm continuing to grow more apart from John, and I should be growing closer to him.''
Nikki could then be seen enjoying tea with her closest girlfriends during her Parisian bachelorette getaway, when she confessed the doubts she was having about her impending wedding.
She told her friends, including Brie: ''Every little part of this wedding, it's like, it's going back.''
Nikki broke off her engagement with fellow wrestler John, 41, over their differing views about having children, but since their split John has said he would love nothing more than to patch up his relationship with Nikki and father her future children.
The pair are not yet back together, but Nikki has claimed she just needs ''time'' to herself before she considers giving John another shot.
His new album Underneath It All is out now.