Under our coats

Travelling by train in a half-empty car, my thoughts wander. The woman opposite me sees the swelling in my trousers. She tries to hide it, but I see her sneak glances every now and then. And she knows that I know. The train bumps, and I "accidentally" place my hand on my thigh, where  I can gently slide my thumb along the swelling.
She gasps, her eyes fixated now. She knows I'm doing this for her and she it is making her hot. Will she play along? She changes position slightly, turning away. Does she not want to play? No, she's just sitting more upright so I can see her hard nipples pressing against her blouse. Apparently gazing through the window, my thumb slides now a greater length. She also moves her finger slowly over her body. Her neck, her breasts, her flank. We go on like this for some time. In the window reflection I can see that she puts her coat over her lap and I follow her example. Under our coats we are touching ourselves, looking at each other, coming.