Quality of sex when wife has emotional connection with other man vs someone new?

My wife has two guys who are primarily her regulars, but one of them is clearly her favorite. I would have to say that there is an emotional attachment between the two of them. They don't see each other outside of our bedroom, but when they are there together the sparks do fly. I asked her once if she loved him, and she responded that she doesn't love him like she loves me. I asked her what that meant and she told me that he is very special to her, and that he is able to stimulate and satisfy her sexually like no one else can, and that she loves that he can do that, so she loves being with him. I asked her if that means she loves him, and she said that she loves him while she's with him.
She's not quite ready to tell you she loves him. Your wife wants to be sure you can handle it, as it's a big step.