She is going to swing!

Will she?
You and your wife have talked about swinging for months. You both like sex and you're convinced that having a little fun (if you both participate) is only going to improve your marriage. You have agreed that no matter who you have sex with, you will only make love with each other.
Your wife is still a bit reluctant. She's worried about how she looks naked, and nervous that sex with others will change things. She's been close to the point of sex twice and backed out. You want this to happen because it opens a door to unlimited sexual experiences, things that you and your wife will enjoy and have said you want to do.
But this time you think it will happen. She said she thinks tonight is the night, but then, she said that before. The other couple are nice. They're experienced swingers, who know not to push your wife but to let her set the pace and take things at her comfort level. Your wife is naked, and so are you and the other couple. He is hard (so are you) and you can tell that your wife's pussy is wet. The wife of the other couple is beside you, her hand on your erection, and she whispered into your ear "If your wife does, I will."
You see the other man's cock as is approaches your wife's pussy. A few inches, then one inch, then a fraction of an inch. Your wife is clearly nervous and excited, but she's been this far before. The other man's cock continues to move forward, and you reach that magical moment. It hasn't happened yet, but it's going to happen in just a second. You're sure of it. She is going to swing!