I'm cool with it, especially if there's a remote chance I might get to watch her with someone else every now and then...hehehe. Just hearing my own little provider/S.O. tell me about her sessions every now and then would turn me on in a big way. Verbally getting those details, and knowing they're real, is more of turn-on to me than reading those good yet probably fake Penthouse Forum stories.
This link will probably hint as to why that would work for me.
Swingers often make rules before they start their type of lifestyle, and that seems to work for some of them (if everyone's head is on right). Based on that, it might be best to have some guidelines agreed to by both parties upfront, so as to minimize and hopefully eliminate any issues. Open and honest communication would likely be important for it to work. For me, concerns might arise if the following were to occur...
1. Her doing things with clients she would never do with me (greek..if she does that, swallowing, 3 ways, etc).
2. Being a provider can't start seriously effecting her sexual desire for me. Let's say she is having appts everyday, and she starts making more and more excuses all the time about not wanting to have sex with me, and that becomes a pattern. Knowing she's having sex with others, but is starting to want it less with me all the time, would be something we'd need to address.
3. Also any of the following would likely be a concern if they started to occur...her not initiating sex as much as she use too (meaning I'm always the one starting it), or her not being into it and and it's getting to where I'm giving too much direction about what I wished she would do next (her being too passive or lazy)
Other than that, feed me, fuck me, don't nag or be too much of a pest, and I'm down with it, lol.