You've convinced me. But I still think I will make it optional because even though it is a joke in the end, it really does make some people uncomfortable. I think it's a win / win if it is still in the game but optional. Yeah?
I am a pretty sensitive guy. Despite hanging around here, I am proud to call myself a feminist, where at least where I live, many women are hesitant to say that. To me, being a feminist means that all men and women should have the same opportunities, that gender discrimination should be made illegal and enforced, that both men and women should be paid the same for the same job, and that girls should be encouraged just as much as boys to enter higher paid professions like business and engineering.
The point I am making about all this, is that I am sensitive to womens' perspectives, and I would not be happy if a game made light of sexual assault or abuse. Some people are fine with it, and to them its just a game, but its not for me. I do not see the vibrator scene as making light of sexual abuse or not taking it seriously. Avalon is in favor of Byron's gift and she should be empowered to feel sexy and enticed by Byron's gift if she wants to.
Now, ultimately, I am still a man, so if there are any actual women out there in the Avalon thread, their perspective means a lot more than mine in this case. If there are any women that find the scene uncomfortable, I'd listen to their reasons and see what you think. Maybe they can convince you one way or the other.
Truly, the vibrator scene itself is pretty mild. Look at all the games here where the MC finds the sleeping LI and undresses her and touches her in her sleep. That is actual sexual assault, and I don't see these same people going to the hundreds of games here with sleep sexual assault and complaining there.
If you change this one scene, I am sure they will find something else to complain about. Maybe they'll say that Penny is unrealistic in her weirdness, or that Dallas is too forward with the MC, or that there is too much humor and that the characters should be more serious (I don't agree with any of this).
Ultimately, it's your game, so you should do what you think is best to make the game better. Is putting a choice before the scene something that will ruin the game? Of course not. I will play and support it no matter what you do, since I love what you have done so far, and I love each of your characters. I just don't know how you will do it where it falls seamlessly within the story, and if were me I would just not worry about a few people who aren't going to like your game anyway, even if you add a choice to this one scene.