Unfortunately, I was my Stepson's first, Oops!!

I’ll start by saying I’m not proud of this story; it really happened...
I’m married and a stepmother to two kids. One of them, an 18-year-old boy we’ll call Bruce, lives with us most of the time because he goes to a community college close to our house. The other, a 16-year-old girl, lives with her mom in the suburbs, where her school is, most of the time.

A few months ago, my husband left early for work, just as I was planning to do something before, he went. I got up, had coffee, and then chose to take a bath. Now that we have a Jacuzzi, I found that facing the front of the tub and hovering while the water jet and bubbles hit my vulva was a nice way to get to the peak.
That morning, I was really excited to come, and I was almost there when Bruce knocked on the door and told me to open it.

First, I want to let you know that Bruce is shy around girls. I had never seen him bring a girl home or talk about them.

Anyway, when I opened the door in my towel, there he was, naked and with a huge, painful erection. As soon as I heard him, I slammed the door shut and yelled, "What the hell is wrong with you?!!" I told him to come back right away and explain himself. After less than a minute, he knocks again. When I open the door, I see that his idea of decent was a towel…