The next day

The next day began early for me. Nathalie's comment last night has gotten me interested and I intended to see what might come of this. Very silently I got up and grabbed some clothes, then I walked to the bathroom. I knocked a couple times and heard Nathalie's voice, inviting me in. My heart was beating fast as I opened the door and was greeted by a fully nude Nathalie. The nipples of her round breasts were standing to full attention. She smiled at me.

"Sorry, I couldn't wait and started without you." Nathalie was giving me a full view of her shaven pussy.
"That's okay I guess. I appreciate the view."
"Come on now, undress. I need a shower." She spoke and so I did.

As I dropped my clothing, Nathalie's eyes were glued to me the whole time. She definitely seemed to like what she saw. My cock was already fully erect when I dropped my boxers, which was no wonder thanks to Nathalie standing there naked, watching me.
After I had fully undressed, we both entered the shower, which wasn't meant for two people, so it was kinda cramped. There was no avoiding our bodies being pushed into each other, which we didn't mind though. Nathalie turned the water on and we got wet. Our wet bodies rubbing against each other made us even more wet, in a different way. Nathalie picked up the bodywash and started covering her body in it, slowly caressing her curves, moving her hands down her sides, back up her stomach and stopping at her breasts. She slowly made rounds around them covering them in body wash, then caressing her nipples and lightly pinching them. She squished her boobs together, played with them. Then she grabbed my hands and put them on her body. I slowly did the same she did before and moved my hands all over her body, following her curves down to her ass. As I squeezed her ass, Nathalie let out a moan. I moved my hands back up her body, turned her around so that her back was facing me and grabbed her boobs.
My dick was between her ass cheeks, so I started slowly moving my hips, grinding my dick on Nathalie's ass. I moved one hand down to her pussy and started fingering her, making her moan.
"I need you in me right now", Nathalie moaned. "Don't worry, I'm on birth control."
Obviously I couldn't resist. I bend her over slightly, grabbed my dick and directed it towards Nathalie's pussy. My cock entered her very easily, thanks to all the bodywash and her being wet. Nathalie immediately started moaning more and so did I. I moved my hips back and forth, first slowly, then faster, fucking my seminar leader Nathalie from behind. This thought was stuck in mind.
'I am fucking my seminar leader, a mature woman, from behind, in a shower with a busted lock, on seminar. Literally any moment someone could barge in.'
That brought me closer to the edge and I sped up my movement. I pulled Nathalie's hair, one hand on her hips, ramming my dick faster and faster into her. Nathalie moaned louder, almost screaming. "Yes! Fuck me harder! I'm gonna cum!"
And so she did. And I did too. With one last thrust into her pussy, my dick unloaded into her, filling her up with my juices. Nathalie's whole body was shaking as she came.
"Wow!", Nathalie said, still breathless. "I haven't been fucked like that for a long time. We need to do that again sometime."
"Gladly!", I replied, also out of breath.

After calming down and (now actually) showering, we got dressed and left the bathroom. Nathalie gave me a quick kiss and squeezed my butt, before disappearing into her room.
'Man, this is the life!', I though to myself.