Fair enough, I can see how that scenario could plausibly happen, yeh. It could also be a way to work towards a potential romantic relationship between Lena and Cindy, if that's on the cards.
The only problem I see with your scenario is considering that Axel cheated on Lena, showing his interest in another woman (even if it's not genuine interest), probably wouldn't be the best way to get back into Lena's good books if he's still interested in or in love with her. I mean, for a lot of romance storylines that jealousy angle would work well, but considering their specific history I think it could just as easily reinforce her distrust in him and drive an even deeper wedge between them.
Not that it's exactly a bad thing either, for the sake of injecting drama and misunderstanding into the story that could be cleared up later. It would just need to be done with real finesse so as not to feel cliche and unconvincing.