Checkitout,
I'll begin with your question ("What should I do?"). You might point out this article to your wife:
Susan Gower on natural cuckolding of husbands by married women:
http://cuckoldcouple.wordpress.com/the-science-of-cuckoldry/
and, of course, read it yourself. Then, talk with her about it. Then, point out this article to her:
Dr. Cherry Lee on the cuckold husband / hotwife phenomenon:
http://cuckoldcouple.wordpress.com/the-cuckold-phenomena/
and... after also reading it yourself, of course... talk with her about it. You and your wife may also find this article:
Musings of an incidental hotwife:
http://incidentalhotwife.blogspot.c...t-other-women-how-to.html?zx=38a6bf4a9736d925
of interest. On this site there are links to many other good articles on this subject, all written by women, which is probably important from your wife's point of view. (The first two articles, above, are also by women.)
Regarding the rest of your post:
checkitout said:
My wife and I have been married for 7 years .... she looks like a model (5' 8", 135 lbs, 34 dd, brunette, green eyes...beautiful). I had always had the fantasy of seen her go wild on another cock, but she was always very conservative about sex. But, as time went on, she started getting freakier and freakier, anal, squirting...
Congratulations for managing to stay married to such a gorgeous hot woman for 7 years. The conventional wisdom, now, seems to be that women's libidos peak when they're in their thirties. You haven't mentioned your wife's age, but she appears to be a good example of that. (Men's libidos, by contrast... meaning, the frequency with which they get it off by masturbating, having sex with a partner, having wet dreams, or some combination of the above... apparently maximize when they're about 18 to early 20's.)
checkitout said:
Finally, around the holidays (x'mas / new years 2014), she was visiting her parents and we started texting back and fourth. One thing led to another, and we started texting about past sexual encounters. Then, she dropped a bomb and told me she had a one night stand with another girl and guy. She gave me details about them both sucking his dick, and laying there while he went back and fourth between them.
Telling you that via text messages from a distant location... after warming you up, as it were... was a good strategy on your wife's part. Since text messages are very impersonal (no facial expressions or other body language), it meant you couldn't "blow up" or otherwise "get confrontational" while, at the same time, she could gauge your response.
checkitout said:
Good. That was the right response.
checkitout said:
Then, she started telling me about all of the other guys she had been with. That made me actually cum in my pants, without jerking off.
Excellent. That was an even better totally appropriate response. Incidentally, it brings to mind:
McManus, David, 2012, Reluctant Cuckold: Who knew a cheating wife could be such a turn-on? (Fannypress, Seattle, 338 pp., paperback).
in which the protagonist — after learning indirectly that his wife fucked another man at a party he attended with her, in the bathroom, where he had knocked on the door while she was doing so, but his wife's female colleague (who — having encouraged her — was also in the bathroom enjoying the show), told him "it's occupied, use the one upstairs" — is unable to prevent himself from ejaculating in his pants whenever he thinks about it, which is frequently.
checkitout said:
Finally, I worked up enough nerve to tell my wife my fantasy about her cucking me.
Good. To realize your sexual fantasies with your wife, thereby enriching your marriage and possibly preventing it from ending, you need to talk with her about them... and, in addition, encourage her to talk with you about her fantasies.
BTW, your wife's forthright description of her threesome and other sexual experiences (did those occur while she was married to you?) mean you are already her cuckold. The definition is, "cuckold: a man with an unfaithful wife." It's short and simple. It implies nothing about the details of the relationship between the cuckolded man and his wife, other than that she fucks other men.
checkitout said:
Her reaction was, mixed emotions. She was shocked and disgusted. But then, as time went on, she got really turned on about it.
Your wife's initial reaction was typical of many married women, as described by cuckolds and cuckold-wannabes in this forum. Her subsequent realization that this would accord with her strong sexuality is very promising.
checkitout said:
Then she started emailing me those captioned cuckold pics.
That's a VERY strong indication your wife is really into transforming your marriage to a "cuckold husband / hot wife" relationship. There's a fair amount of online literature and discussion of this (including, of course, this forum). It sounds like your wife may be reading it.
checkitout said:
But, as she started to really want to do it, I started getting cold about it. I didn't tell her I got cold, but I did.
That's not surprising. The judeo-christian tradition, which continues to be very strong throughout western societies, is... even today... that a married woman is "owned" in some sense by her husband. Ergo, a married man or even a man in an LTR is supposed to find it shameful if his wife is sexually liberated and dates, seduces and fucks other men. Thus, in most cases it's probably best to keep "cuckold husband / hotwife" relationships discrete with respect to relatives, conventional friends and work colleagues. I.e., it's probably best to seek a new circle of friends who share this interest.
checkitout said:
I still get super hard thinking about it...
As you should...
checkitout said:
...but, after I cum, I feel like I could never truly let my wife do it.
Let should be "let" because your wife already has done it. Probably you should make it a point to not think about all this immediately after you cum, because then you're sexually satiated and more prone to revert to thinking in terms of conventional social expectations. (This is among the reasons a fair percentage, it seems, of cuckoldress married women insist their husbands wear male chastity devices and become their sole key holders. That way their husbands can't masturbate themselves to orgasm without their permission.)
checkitout said:
The way my wife talks about it now, I don't know if I can (or want) her to turn back. When she talks to me about it I can see her pussy leaking through her pants, and when I talk with her about it during sex she squirts so much that it leaves a puddle on the sheets.
Whew. That's really impressive. Since your wife obviously has a strong desire to make you her self-acknowledged cuckold, it's unlikely you'll be able to continue resisting for much longer (IMO). This, I suggest, is the most realistic answer to your last question.
Your transition to a “cuckold husband / hotwife” form of marriage will be easier and will have greater potential for long-term durability if your wife becomes the acknowledged dominant partner in your marriage. A strategy for accomplishing that transition that may appeal to her, and you as well, is presented by Lady Misato:
Real Women Don’t Do Housework:
http://ladymisato.atspace.com/introduction.html
(work through the chapters listed at upper left sequentially).
Thanks for your interesting and erotic post, and good luck!
—Custer