Besides Alexis , are there any other NTR in the game ?
There's a couple scenes. If you don't romance Sasha there's an event where you find her blowing her ex, you can find Bree and Sasha fucking in the shower if their lesbian scores are high, Lexi has an event chain where you can choose to pimp her out to Jack, there's a one time event where you can pimp out one or all of your co-workers for extra cash, and Aletta is sleeping with Dwayne for one of the storylines with a scene for group sex with her with Dwayne and you with Lexi. And depending on your definition of NTR (because apparently everyone has their own) there's MFM scenes with Sam, Sasha, and Lexi.
For anyone afraid of the NTR boogeyman, you have to pretty much intentionally trigger these scenes and some of them have obscure conditions to start them.