Did I Catch Her, or is it My Imagination?

Last weekend I went to a large amusement park in the state I live in, for a long weekend with a female friend. We are just friends...we have never even kissed. She is more than a decade younger than I am, and incredibly attractive. She doesn't have her 20 something year old body anymore, but she still looks awesome. I have never seen her naked, but she is hot in a bikini!! I have let my imagination run wild a few times with thoughts of her. I have had many orgasms thinking about her. She thinks I am too old, because she still likes to play with the 20 somethings that are still incredibly fit! She is about 5'5" tall....I would guess 135-140 pounds. Beautiful ass with 36C breasts. She has a smile that makes me melt when she flashes it. We were supposed to have a larger group, but everybody else who was supposed to join us had something come up. It was just the 2 of us for the whole weekend.  We were staying in one of the beautiful resort hotels within walking distace of the park. We were lucky enough to be on the 11th floor with an awesome view!! We have stayed in the same room several times....always in separate beds. She always has her phone on...reading an interesting article, facebooking, redditting, selfying, watching a video or program,  etc... It is not uncommon to wake up and see her on her phone.  On the second day, we had been enjoying the park, eating, drinking a lot, and enjoying all of the views. It is amazing how many beautiful people are at this place!! We both got eyefulls of what turned us on all day!! We got back to the hotel aound 11, and had another glass of wine before we went to bed. We both showered and got into our clothes we slept in. I chose running shorts and a T-shirt, and she was wearing loose fitting shorts and a tank top with no undergarments. I was trying to watch the end of a ballgame, and she dozed off. I could hear a quiet snore every once in a while. I turned the game off, took my T-shirt off, rolled over, and drifted off to sleep myself. I am normally an early riser, and I am a fairly light sleeper. I woke up around 3:30 and heard light rustling in her bed. I quietly rolled over and took a look to see what was going on. She had cocooned herself under the sheets and seemed to be watching a video. It was interesting at first, and thought how considerate it was to do that as not to wake me up. She had her earbuds in, because there was no sound, and it was a video she was watching. Her sheets rustled more and more, and I thought I heard her breathing increase just a little. My senses tingled a bit, and my cock started to awaken. I thought I saw flashes under her covers....like she was taking pictures of herself. My cock was now at full attention!! I could not see her, but sounds are just as enlivening as seeing things. I could hear her playing with her pussy. It was muffled, but I could hear the sound of sticking her fingers into her lush pussy and using them as lubrication. I couldn't stand it anymore. so I quietly pulled my shorts down and started to slowly and softly play with my cock. I was mesmerized by all of the light flashes of the video in her cocoon. I couldn't see the red tank-top she had been wearing...just her bare shoulders. I could hear muffled sighs and her breathing was not normal. She had to be masturbating. My mind just took over. and I imagined her in my bed with me. Her beautiful breasts with rock hard nipples!! Her in front of me playing with her beautifully shaved pussy. I was trying to be quiet, but I know I was making that stroking noise. I was so turned on that I didn't care. I think I wanted her to catch me!! After about 10 minutes of her pussy sounds and sighs, I couldn't stand it anymore, and started to stroke faster. My balls were absolutely full after no contact for 3 full days. I finally exploded under my own covers sending ropes of cum onto my belly and chest. I got some on the covers, and was in pure extasy!! My eyes never left the sight of her back to me watching and masturbating to a video. I cleaned myself up with the T-shirt I initially wore to bed, and kept watching for a few more minutes. I had to pee, so I finally got out of bed which she heard. When I came out of the bathroom, she was laying there facing toward me reading her phone like nothing had happened. We haven't talked about it....at least not yet.