I LOVE playing with couples and I do it frequently. I enjoy it so much that I don't ask any extra for a client to bring his significant other (SO). It's the same cost as for a single person.
I've done it quite a bit, I have some important advice and will share it with everyone, because I think it's important.
First, this is NOT something that should be a surprise. It's kind of like giving someone a puppy. It really needs to be openly discussed first. If you push too hard, too fast, and it doesn't work out, you may never get to have another threesome, so it's worth it to be patient and do it right. Always make it about the SO.
Secondly, you want to be sure to choose a provider who does not bring out the insecurities of your SO. Let her help you choose. And keep in mind if she's saying no to someone, it may be because of her own insecurities. You don't want someone younger, thinner, more fit, or with nicer boobs, lol. Even the ladies who see themselves as sexually sophisticated enough to do this with you may still have to convince themselves that you aren't using this as an excuse to play with someone you find more attractive than them in some way. Your SO other should be more attractive than the provider who joins you.
Thirdly, and most importantly, NO MATTER HOW DIFFICULT IT MIGHT BE, make sure you don't give excessive attention to the provider during the session! Make sure that the session is at least 80% YOU being into HER, the SO. You'll still get your threesome, and make her feel that she's turning you on so much my doing this for you. Because it really is a gift for a lady to let you bring another lady into it.
Avoid what might be considered intimate acts such as deep kissing and meaningful eye contact with the provider.
Finally, even if you do all of these things exactly right, be prepared to ask the provider to leave the room to go get a drink or something and check in with your SO to make sure she's okay with everything. Have some sort of pre-decided code so either of you can have a time out if you need one.
Most of my couples sessions are pretty awesome. I think one reason is because I insist on having a speaker phone conversation with both parties and I discuss the above issues. But, when it doesn't work it can be really bad. Everyone can tell when the lady (SO) has hurt feelings. I hate to continue the session, she doesn't want to be a party pooper and ask for an early end, the guy will probably be in trouble for something and never get another threesome...often the lady even has tears in her eyes and it sucks.
I'd say about 85% of my couples sessions are successful and 15% of the ladies have a problem with it.
To summarize, even if it's about you, really...you've got to make it all about her or probably will not be a successful encounter. Let her know how sexy you think SHE is for doing this, before, during, and after. Be super careful about her feelings. Men and women are so different when it comes to sexuality. If she feels threatened, and that can happen SO easily and even when every consideration to her comfort is being given, then that might be the end of your threesomes.
I hope sharing my experience will help everyone circumvent the potential pitfalls of couples sessions.
xoxo