We don't know yet.
Chapter 12 got all the setup to force Cindy to make a move when she is back.
- Ian can be clearer on her (show devotion with a present, demand clarity, breakup, high lust), which already influenced Cindy when she was texting him.
- Lena may sabotage the relationship if she sleeps with Wade. This isn't clear either, we don't know if Wade always refuses if he is still good with Cindy and if Lena even goes through with it
Once she returns, Cindy has to make a stance on Ian/Wade/Axel, else this plotline is disappointing and dragging.
Possible, but I wouldn't be surprised if she isn't fucking Axel on the yacht (yet).
If Lena can seduce Wade even if his relationship with Cindy is better, then a faithfull Cindy has even more reason to break up with him and it makes Lena even more of a homewrecker. It would also give Wade blame to the failing relationship, rather than given most of the blame to Cindy, who is obviously a cheating slut!!!
While Axel makes some moves on her, overall he playing it out and waiting until Cindy becomes single and angry about her breakup. Then she is vulnerable and incentive to start a new relationship. Ironically, Cindy isn't the cheating type per principle, she values relationships and monogamy. With Ian, there were multiple very emotional exceptional developments that led to the affair, but with Axel its more of a new job opportunity and no emotional investement.