Yes, she doesn't hit on you, i say that. But she is one of the main love interest of the game, so she is there a big deal of time and many of her lines are designed to be "neutral", meaning that they work either if MC is in a relationship with here or not. Therefore, if MC let her down, those line appera kinda out of place and cringy. And all here wardrobe malfunctions like "Oh! You can see up my skirt! Oh! My oversize boob just slip out! Oh! I just grabbed your considerably big penis by mistake.." may be very annoying if you really aren't interested in pursuing the route. Or even gross, if you literally hate Monica as a character as i do.
I'm not criticizing CheekyGimp's work as a whole. This is by far one of my favored games here, and easely one of the best in general on the platform. I admit that i personally really don't like the MILF routes, but of course there must be something for every taste in this ludic world. What i really hate is when you are forced in a MILF route as some game do. It is, of course, not the case with WTHI, which is damn well designed and allow the player a lot of freedom of choice. Yet IMHO,
Monica is somewhat of a downside. Yes, of course you have no obligation to get involved with her, as i said above, but she still often behave as you where, anyway, and, with my full honesty, in my own experience with the game, it turned to be very unpleasant and annoying.
Zarah, for istance, is a perfect exemple of a better designed MILF interaction. She has her own agenda, she tries very hard to seduce the MC and even to have him go after Monica, but when she is let down she behaves more normally.
As i said, i'm not attacking the work of CheekyGimp on any level. It's just my honest feedback on my personal take on the game.