I really don't know if 'FF' is right, you decide.
This happened during a convalescence from a car accident. I was badly hurt and spent a long time at home when I came out of hospital.
The injuries I received were life threatening, and involved many operations to correct the damage to bones and joints. As part of my convalescence, as my wasted muscles were forced into use again they used to protest, having my crying in pain after my physio.
Mum would lay me down on her bed, on a towel, and massage the muscles of my legs and lower spine until they were no longer tense. Usually, this took over an hour and started off with me in complete agony, but as she worked I relaxed until the pain went away.
This particular day started the same way. Pain, searing, white-hot pain. As mum worked, the pain receded faster than usual. She rubbed my calves, then my thighs, my ass and my back. As she worked up my thighs, I felt something. For the first time since the accident, I felt the unmistakable feelings of arousal. It had been a very VERY long time since I could take care of myself. As mum worked, I felt my tummy tingle, followed by my breasts feeling really sensitive against the rough toweling. I had panties on, but I knew I was getting wetter by the second.
Mum's fingers moved higher to my panty line and my arousal went with them. I tried so hard to control my breathing, but, damn, mum's fingers felt so good as they kneeded the tense knots in my ass muscles. Then I felt her move between my legs a little.
I had better say here that nothing she did was in any way unusual, and I am quite sure she wasn't trying to turn me on. She was though, a lot!
I knew she would slip her hands under the legs of my panties and would grab both my ass cheeks and work them. As she did this, I just knew it was going to make me cum! I concentrated on my breathing and NOT making any noise.
When the orgasm hit it did so like a tidal wave. I felt my pussy contracting (sadly, on nothing) and I knew I was squirting a little into my panties.
Mum kept up her usual routine and said nothing. Then, she moved to my lower back. This time, though, instead of the pummeling I usually get it was more of a soft, mid back to feet long stroking action. I relaxed after my tremendous cum, and let her calm me down.
At the end of the massage, she would usually let me sleep for a while. She walked to her bedroom door, paused, turned around and said 'Next time, Kate, if you cum, it's ok to make a noise. I know you haven't been able to look after yourself, and I will never do anything to deliberately make you aroused, but if it happens, well, I won't stop it either.'
She turned off the light and left me to snooze.
It did happen. About three weeks later. Same thing, except this time I gave into my normal moaney self. As I came, I even managed a couple of 'Oh fuck, yes!'
Mum never fingered me, or anything like that but she knew that as she moved my ass, she would inevitably move my pussy too.