As Mac said in between lines, cuckolding is among married couples.
That said... to me, the stronger the relationship, the higher the turn on.
Usually marriage is supposed to be stronger and lasting longer: so I definitely vote WIFE.
I didn't have cuckold-like fantasy with my (then) gf (now wife).
I certainly do have cuckold fantasies now that we have been married for +20 years (it started 15 years ago)
I like stories of unfaithful wives, I usually don't care those of unfaithful girlfriends.
An exception, from real life:
happened to a close friend of my wife's two sisters (all very cute). In spite her boyfriend's advances, she refused to have sex with him because she wanted to get vergin up to marriage (!)
I witnessed discussions about it among her and two sisters (moderate turn on).
It lasted three/four years (!!!) she denying her sex to poor guy.
One summer, when in vacation with parents, she ended up fucking her horse riding trainer.
All the community of friends knew, but him.
They eventually split after a couple of months.
He is still around, still bachelor, not much sexual activity we presume
She vanished.
When I think of her fucking the horse guy, I still have huge hardons.
(Unfortunately, I did not witness when she told the story to my sisters-in-law. But I surely was present (and clearly rememebr
) when sis-in-law told to my wife. I wanted to jerk off on the spot !!!)
Real story, I could give you names and surnames.
- GordonPym