We were at the Spa, the lights were dimmed but the jacuzzi that we got in had it’s own lights, so we could clearly see each other.
So we got in it, only three of us, me, my girlfriend (24 years both of us) and her sister(22 years old).
I set near my gf and her sister was right in front of us, there were lots of bubbles so you could barely see through them.
Without much thinking and warnings, I started slightly touching my girlfriend’s pussy, she instantly looked at me and smiled, letting me know to continue, so I pushed two fingers in her, moving them slowly. My girl started to talk with longer pauses, her sister didn’t notice anything (or did she?).
But this was not the end, at the same time, my girl started to touch my dick and eventually doing me a handjob(also slowly without sudden movements)
I was looking at both of them, like nothing is happening and even joining the conversation.
Her sister still didn’t noticed anything, or, maybe she did but we will never know.