I find this particular thread to be very interesting and I'm surprised that more Bulls have not weighed in. With this being the case I will give you my opinion from a Bull's perspective.
Being in the lifestyle for as long as I have it's inevitable that you hear stories of wive's leaving their husbands for a Bull. Honestly, this is something that I've never really fully understood. Don't get me wrong, I can understand that occasionally this happens when the Bull falls for the wife but I would wonder how often that is actually the case. As I'm sure any experienced Bull can tell you, when you're dealing with a wife, especially one that is new to all of this, you have to be careful about letting her become to attached to you. I say this because more than likely, you are the one bringing something new and exciting to her life so you have to be keenly aware that there is a chance that she can fall hard for you. Personally, I think some Bulls get carried away because they've never experienced the level of attention that can come with being a Bull to a wife who is new to this. I'll be honest, it can be quite the ego boost.
One of the things I have always enjoyed about having another man's wife is that I get to enjoy all of the sexual benefits without having to deal with all the real life aspects that come with actually being in a relationship or married to her. As anyone who has been in a serious relationship can attest to, no matter how mind blowing the sex is, we still have to deal with the day to day 'mundane' stuff that comes with it. (complaining about work, family issues, health issues, children, finances etc). Trust me, I live with 2 women so I'm getting real life issues in stereo lol. So why any Bull would want to take a wife away from her husband and family just doesn't sit well with me. I blame him more than her because he is the one that should be keeping his feelings in check. I look at it like this...just because you can do something, doesn't mean you should. I have been with more than my share of wives and never once did the thought of taking her away cross my mind. Why should I? I can get her whenever I want to and can send her back home when I am done. As I said earlier, I'm sure there are a few cases where both wife and Bull fell in love..I mean genuine love, not just infatuation. If that's the case, more power to you. But if you just took her because you could or for some other reason then I really don't think you were truly cut out for this lifestyle to begin with.
Again, this is simply my opinion and I welcome any further dialog on the matter.