I can only speak for myself here, but what I get out of being cuckolded by my wife is a bit complicated. First off, I get the satisfaction of seeing my wife in ecstacy. It's not simply that she's getting better sex... granted, it's definitely more intense, but we have satisfying sex when she's not with a bull. There was nothing broken in our love life before we started doing this. It's more accurate to say I derive pleasure from witnessing her pleasure. Look up the word "compersion." That word definitely applies in our marriage, but even that's not the whole picture.
I was submissive and my wife started keeping me in chastity long before she made the leap into cuckolding me. Tease and denial isn't truly about sexual inadequacy. For me anyway, it's about being kept in a constant state of arousal and desire for my wife. Whenever men get a full release, chemicals flood the brain that create a sense of satisfaction, and the chase is over. This is where we get the stereotype that men will roll over and go to sleep without cuddling or making sure his wife is satisfied. In practice I don't think most men are completely that cliché, but being teased and denied orgasm can keep a man constantly in the heightened, horny state of arousal that you might experience from intense foreplay, right up to the moments before climax. Being denied that release can obviously be frustrating, but it can also make a man laser focused on serving his partner. Taking away the possibly of release, or at least making it more rare and never guaranteed, means that climax is no longer the man's goal during sex. When I've been pent up for a couple of weeks and have come to expect that sexual activity more than likely won't involve an orgasm for me, my entire goal shifts from my own pleasure to the exclusive pleasure of my wife. I want to keep massaging her, worshipping her, kissing her, licking her, fingering her, devouring her and even fucking her (if she decides she wants to unlock me), for as long as I possibly can, relishing every single movement she makes. I react to every muscle she flexes, every change in the quickness of her breath, every word or gutteral sound that escapes her lips. My goal becomes exclusively to have her writhing and panting and screaming and bucking against me for as long as she will allow me to do it, and her satisfaction is my reward. I cum only if/when she tells me to.
So for us, cuckoldry was a logical next step to take from chastity and femdom kink. We describe our marriage as a female led relationship (flr), so my position as her submissive is pretty much constant. Having long been the dominant one in our relationship, she wanted to be able to explore her own submissive side, but it just never felt authentic for me to switch roles and try to dominate her. She does not see me as dominant, she sees me as her sub. A lot of our play involves weeks of teasing, so even if we could "pretend" and switch roles, she'd lose all the progress she's made in breaking me and making me her slave. It just made more sense to outsource. When she started seeking other men, she gravitated toward men that are nothing like me or the role I have in our relationship. She could indulge in her long held attraction to black men, she could play with men who spend the bulk of their free time in the gym or fucking, making them ideal playmates, even though that's not what she needs in a life partner at all. She doesn't wish I spent all my time working out, she likes that I'm an attentive caretaker, co-parent committed to selflessly raising our children, and a full partner in running our household, our finances, etc. She likes that much of my free time is spent being an artist, programmer, etc. That's not to say I don't take care of myself or that she wants me to be out of shape, or that she doesn't want to be with men who aren't two dimensional, simple, beefcakes... balance is important and she's not shallow at all, I'm just saying that what she enjoys in a sexual partner is sometimes very different from what she appreciates most about me as her life partner.
Once she started fucking black men, ranging from pretty good physical shape to impeccably sculpted, from mildly assertive to extremely dominant, from slightly above average endowment to obscenely hung, she developed a newfound appreciation for what being submissive feels like and what I get out of it, and she became a much more engaged and creative Domme. So that has been a very tangible benefit I get from being her cuck. Our femdom play has been taken up several notches. I've also watched her do things with other men that she's never done with me. A lot of people (perhaps understandably) wonder why I don't demand she do them with me, but again it comes back to authenticity. I am her sub, and she acts accordingly with me. Acting the way she does with her bulls isn't a conscious decision, it's a natural reaction to being with men like them. It's not her natural reaction to the way I play with her. So she could, for example, decide to be nice and give me more blowjobs, but that isn't the same thing as the way she hungrily worships and devours and gags on the big cocks of her strong, black bulls. You can't fake that hunger, and we never even would have known it existed within her if we hadn't decided to explore this path together. Cuckoldry has helped my wife develop and explore a whole new side of herself, and getting to see that in her is an extremely erotic and rewarding experience for me. It's not always easy, and there are moments of breathtaking jealousy, but clearly it adds a whole new level of intensity to our tease and denial play, it allows her to explore both sides of the spectrum from dominant to submissive, it's great for her confidence to have so much fantastic sex, sneaking away for a naughty tryst here and there reduces her stress and makes her happier at home, it lets us experience new dynamics we never had before, it's necessarily increased our communication and attentiveness to each other's desires and needs, and has generally helped us truly grow as a couple.
We're not damaging our relationship, nothing she does makes "a little bit of me die," and I certainly don't "lose a little bit of love and respect for her," as your Kik friend describes. Quite the opposite. I admire and appreciate her more and more. It's complicated, it's hard to explain, and it's not something I recommend to everyone, but it's made our marriage stronger than it was before. You know the expression, "if you love something, set it free?" Imagine how much faith you would have in your relationship if you literally put it to the test like that on a regular basis. My wife has every bit of freedom she could possibly want and she always comes back to me. Not everyone is cut out for it, but I absolutely love her more than anything and am reminded daily how lucky I am to have a partner that understands, accepts, cares for, supports and appreciates me the way she does, and I absolutely love helping make sure she gets to enjoy whatever she wants.