She is too stunned

Nikki stares at you unblinking for a few seconds as you grab your breakfast and head back up to your room. You can't believe you said that, you promised yourself you wouldn't do anything like that when she married your dad.

"God fucking dammit..." you whimper as you slam you your fist into your pillow, "Why am I such an idiot."

It was your fault she had grown closer to your father after all, so afraid of your own feelings that when she was thrown out of her house after coming out, you vetoed against her staying in your room after your father let her stay with the two of you. If you had only said yes, it would be her plowing you every night instead of your father plowing her.

You look over at the clock as you hear muffled sounds from your parent's room, Nikki likely looking for things to get herself off before driving the two of you to school. It wasn't a bad idea, you were horny as well... but you didn't want to get off in the clothes you were going to wear to school.

You climb under your bed, pulling out a large suitcase and open it up, its filled with lingerie, skirts, and other girlie clothes as well as a large dildo. Unlike Nikki you didn't view yourself as a woman, more of femboy or tomgirl. You still identified as male, you just liked wearing girlie clothes and riding dildos.

You quickly get changed into a nice set of black crotchless lingerie https://cdn-img3.iporntv.net/videos/201909/27/251310172/original/(m=eaf8Ggaaaa)(mh=kJKscYEWR2g8v_1I)7.jpg to ride a dildo too, and start setting up to ride it as you hear your door creak.