Is Cuckolding ok just as a fantasy?

[Bullstallion]

I believe cuckolding is a very common fantasy many (man/woman) have. We are married for 10+ years and are happy emotionally physically and in all aspects of life. Our sex is still good as well but I have wife sharing fantasy. When I say this it is just threesome and just inviting another (man/woman) onto our bed. As in most cases wife is not ok with this. But did not push back completely (this is somewhat a regular chat we have on bed). To me it's clear that she is not interested as she is completely satisfied with me. And honestly, I don't think even I will let anyone (man/woman) come join us.

And in my case atleast this chat helps in spicing things up. Can someone give me a perspective on this. If continuing this fantasy weakens me and would increase my want for it? Is it okay to just fantasise and enjoy with some extra spice like roleplays etc?

Bang on. We're mostly on the same page on this topic.
We've been married for 14 years.
And still this fantasy keeps banging in my mind.  Basically, it's been a long time, just me fucking my wife and enjoying her lusty beauty. 
Now, to spice it up a little, I've started exposing her / showing her off .. 
I have shared lot's of her pics here in xossip as well. ( Face blurred ofcourse)

Now, getting her to fuck another man, that too with my consent and my presence there, is a daunting task.

But, I'm slowly slowly getting better at dropping hints at her , esp when she's horny during sex.