My girlfriend and I have been together for 3 years.
We've got a pretty good relationship but as with most couples our sex life has reached that point we just do the same things repeatedly.
As she was rubbing her clit up and down my cock to get wet, out of nowhere she started chatting about the swinging scene and did it turn me on, then on to would I like watching another guy inside her.
She must have been keeping the same feelings as I had as her pussy was dripping within seconds.
A few weeks ago while watching a movie that had a swinger scene in it I threw in the comment, "Imagine actually doing that," which to my amazement she replied, "It would need to be a classy one." I almost froze with excitement and shock.