Well, she's talking to you pretty weird. And you have options to question her... Those are clues that something is up. There is also foreshadowing in MC's description of her earlier in the game: she's cool and in control and used to getting her way.
Perhaps you could miss all that, but it was definitely there to be noticed.
Now, if you missed all that and accepted her offer, you're on rails for a bit and I hope you made other decisions correctly because there are worse things than eating your own cum. Still, you will get opportunities to jump off. In fact, we don't know what the consequences to your eventual relationship with her are if you jump off. It might even be the "correct decision". She's new to the femdom thing, isn't particularly good at it, and seems, to me at least, not to really have her heart in it.
This path is a polarizing one. Many, many people don't like it (me included). I don't even know if folks who like femdom like it. Wonder why dev put it here? Especially if you play other paths and find out lots of different information about the characters...
Could he have nefarious plan or is he just going the something for everyone route? Let's find out together!