My family and my friend's family have often rented a vacation house for one week in the summer at a beach town in our state.

I got started on a family later in life, so while he and I are the same age, my kids are in grade school and his are in college.

Last summer, we brought my kids to the park and ice cream, but his oldest daughter (20) stayed behind. I forgot my wallet in the car and ran back in to get it and had to walk past her room. Door was open, she had headphones on, facing away from the door watching porn on her laptop. One hand was pinching her perfect pink nipple while the other was guiding a dildo in and out of her pussy.

I froze, got hard, stared long enough to lock it into memory, and use that memory often.