On Tracy's back, or your wife's face?

As you make your announcement, your wife pushes Tracy out of the way and reaches for your cock. Tracy turns around also, and they both grab your erection and bend their faces toward it. This surprises and excites you immensely as your wife has never before taken such a keen interest in sucking your cock.

They both end up simultaneously place their tongues on your hardon at the same time.

Your wife eventually slides it in her willing mouth while Tracy runs her tongue up and down your scrotum.

After just a few strokes you can take no more, and pull your wife's head just inches away from the head of your dick and explode over both their faces.