Thanks guys. I really like the last two comments.
Hey, man, I hope things started going better for you in your quest. I thought it might raise your spirits to know that it is indeed possible to come back from such a place, as my wife and I had our first threesome experience this past weekend. I don't want to go into too many details about how it went down because I want to ensure anonymity, but the particulars of what led to the first experience itself are less important than the process.
The key things I would advise are to not put too much pressure on, to be persistent, and above all, to be patient. Hints and teasing are essential, but they're only going to get you so far if A) she doesn't know that you're also serious about wanting to do it on some level (which she now does in your case), and B) you don't make it known to her every now and then that the option is available for real
without making it a high pressure thing. I'm not saying you sit her down for a heart-to-heart and reveal how important this is to you; that's making way too big a deal out of it, and thus it becomes pressure. You only want to associate positive feelings with the idea.
Talking about it during sex, particularly when she's orgasming or close to it, is a great way to associate positive feelings with the idea. The closer she is to orgasm, the more her defenses will be down and thus the more her true feelings about the idea will be on display. That said, she's not always going to be receptive to it, even if she's seriously thinking it over in her mind, so use your gut, discontinue immediately if she's not receptive, and
don't overdo it. Those would all be negative feelings, and that's the last thing you want her associating with the idea. You also don't want to run the risk of her thinking this is the only thing that turns you on (hint:
she should be the thing that most turns you on).
My last point is somewhat related, and that's to only bring it up when the vibe is right, and I don't just mean the sexual vibe. You should know your wife well enough to know what I mean by this. When she's in a good mood, a silly and playful mood, and things are just positive and high energy, that's when you want to drop a hint or a tease. If you're just coming off a fight, or she seems tired or grumpy, or had a long week, resist the urge. You're only going to hurt your chances by bringing it up then because people are predisposed to recall the negative aspects of a thing when in a negative mood and the positive aspects when in a positive mood (and she'll have both feelings about it, just as we all have both feelings about everything in our lives, including the things we love and hate the most). It's just human nature. Use it to your advantage.
The fact is, I think you're closer to it than you think. In our case, she said she only ever wanted to be with me as recently as a month or two ago, and last weekend she had a big black cock in her mouth and filling her pussy, and both our libidos have been through the roof since. At this point, it feels like it may have actually improved our relationship, which is a beautiful thing.