No reaction at all; see where it goes

You decide that the best reaction in this situation is no reaction at all. You'd definitely have to think long and hard before making any sort of move on your mom, yourself, but at the same time, you're not completely closed off to the concept. You've never really looked at your mom in a sexual way; you resolve to discretely check her out at the next opportunity you receive. She apparently has the jones for you; you should see if you feel anything in return.

You close up the computer, careful to leave it the way you found it, and head downstairs to your room. You still haven't scratched your ejaculatory itch, so you pull out the shoebox from under your bed that you use to hide your masturbatory materials. Underneath a few school papers, you have a few letters from girls you had the hots for, a stack of photographs of various friends, a handful of condoms, unlubricated, that you sometimes wear when you want to masturbate in bed, and a few Victoria's Secret magazines that you've swiped from the mailbox. Usually, when you can't use the computer upstairs because someone is around, you just come down to your room, get out a magazine, and combine the curves on the page with a face in your head in the bathroom until you squeeze one out. Today, you feel like staying in the room, so you open up a condom, put it on, and peruse the pages of a magazine until you find a picture that really turns you on. You begin to jerk.

Your efforts are interrupted by a knock on the door. You quickly toss the magazine back into the shoebox, put the cover on the shoebox, and stuff your condomed penis back in your pants. You straighten your clothes a little, and ask, "who is it?"

"It's me," you hear your mom's voice reply. "Laundry."

"Oh, I, uh," you reply, not sure what to say. She apparently takes that for an invitation to come in, and the door opens up, and your mother walks in, with a basket full of laundry. "Is it all right if I put this away?" she asks, and starts moving to do so without waiting for an answer. You try to stand so as not to reveal you have a fierce erection. As she walks past you, she has to squeeze to get past the bed, and you feel her hip brush across the front of your pants, pushing against your boner. You pray that she thinks it's just your leg. Once past you, she bends over, opening dresser drawers and putting away your clothes. She is wearing a tight little pair of nylon shorts, and you can see the outline of her panties through the thin fabric that stretches tautly across her round ass. You had never really noticed it before, but she has a very nice ass. She turns around to ask you something, without standing upright, and you have to struggle not to stare at her hanging cleavage as you stammer a
response. Her breasts, it turns out, are just as nice as her ass. Your erection, far from going down, has only gotten worse since your mother walked into the room, and is uncomfortably stiff. You watch as your mother puts away all your clothes, unable to turn away from her hot body. Before long, she is finished, and she stands up to go. She looks around the room, to see if there are any dirty clothes to take to the laundry room, and you see her eyes linger on the shoebox on the bed. She says nothing though, and since there are no dirty clothes laying around, she says "bye bye" sweetly, and moves to walk out of the room. You are standing in the same place that you were when she entered, and again, her hip brushes firmly against your crotch as she walks past. It's doubtful that this would "accidentally" happen twice, but you suspend your disbelief, and watch her walk away.