>>1725
>Now obviously I don't want to satisfy this fetish at the expense of my girlfriend's happiness, that would be terrible.
Best possible sentence to read in one of these. You're alright. I'll answer your question.
>But I'm wondering if any guys here introduced this fetish to their girlfriend, had a rocky start, then finally made some sort of breakthrough where they ended up liking it?
I kind of did, but my circumstances differed from yours.
My girlfriend (who is also my sub) fundamentally experienced sex as a way to serve me and derived her pleasure from mine. One day, I offhandedly joked to her that having a mistress would be handy. She said that it would, but that she would never be able to bear sharing me. (It's worth noting at this point that we trusted each other absolutely - for either of us to cheat was unthinkable. She never minded me looking at other women, either; she would even point out the occasional nice pair of legs for me to ogle on the street.)
So we laughed it off, but I got curious about how one actually does get and keep a mistress. The answer, from my research, seemed to be "have a lot of money and lie a lot". But while I was researching it, I stumbled across the cuckquean fetish. It blew my mind.
When I told my girlfriend about it, she agreed that it made sense that it had to exist but was aghast at the idea. Hated the idea of doing it. No more was said for months.
Then one day as we were lying in a post-coital puddle, she confessed to me that she'd briefly fantasised that the squelch of pussy juice around my cock was from another girl and that to her complete shock, she hadn't really minded.
There's much more to the story, but that's the part that answers your question.
>And how did you convince them?
I didn't. I focused on training her well and being a good master to her. She reached the conclusion on her own that it was something she wanted to do for me and something she'd maybe enjoy.
After she mentioned that it was something she wanted to consider, I helped her explore the idea slowly and safely. Then once she was sure she wanted to try, I trained her for it. Then I carefully guided us as we actually explored it step-by-step.
Now she blushes and makes excited little whimpering noises when I remind her how much she enjoys sucking another girl's juices off my cock after watching me pound them.
That said…
>I introduced the fetish to my girlfriend and she hated it. She gets anxiety that I'm going to cheat on her and it's affected her so bad that she had to unfollow a bunch of porn blogs on tumblr that featured 3some porn even if it wasn't overtly cuckqueaning.
You're not just dealing with "nah, that doesn't appeal to me" here - you're dealing with her being so anxious that she changes her behaviour to try and ward off the anxiety. Until she can trust you and no longer get anxious that you'll cheat on her, the possibility that she'll like cuckqueaning is probably out of the question.
Good questions to ask yourself and maybe her: What's at the root of the anxiety? What part of the cheating makes her anxious? Does she imagine you leaving her for the imaginary other girl? Does she imagine being kept in the dark while you betray her? Does she derive security from being your one and only everything? Does she actually think it's likely you'll cheat on her, given the chance?