Fitness Fever

Begin this stimulating roleplay by setting up an outdoor gym at your home. As a gym trainer, you need to focus on delivering a professional and challenging workout session to your wife. As she performs the given exercises, let your hand graze against hers and make sure to help her perfect her techniques. Make each other feel the burn and ignite erotic tension.
Remember to maintain the trainer-client professionalism throughout the session. Correct her postures, show her techniques by touch and constantly praise her efforts, all while maintaining an underlying current of sexual tension. As the workout intensifies, so does the erotic atmosphere. Let the adrenaline and endorphins mix, leading to a climax of the workout.
The session concludes with a cool-down routine. This is where the passionate couple side of you both takes over. Slow stretches with romantic eye contact sets the tone perfectly before you enjoy the culmination of an evening of a healthy, arousing activity.

Firstly, you'll need to set up your outdoor gym. This does not need to be an extravagant arrangement. Basic workout tools such as dumbbells, yoga mats, resistance bands, and skipping ropes will simply suffice. Arrange these tools in an open space where you can easily carry out your workout scenario.
Next, you need to get in character. As the gym trainer, you need to look the part, so dress in appropriate gear. Don't forget the stopwatch to add an element of authenticity! Prepare a 'workout plan' for your wife, similar to what a real personal trainer would do.
Finally, have your partner dressed in her favorite workout gear. Remind her that she is a dedicated workout enthusiast ready for the challenge.

Remember to maintain a professional quotient in the beginning and escalate it gradually. It will seem more realistic and hence, much more exciting.
Safety first. While it's easy to get carried away, ensure you both know your limits when it comes to physical exercises. You don't want any injuries ruining the fun.
Lastly, keep the atmosphere charged. Regularly use suggestive comments and hidden compliments to keep the spark alive. The beauty of this scenario is the growth of sexual tension emerging from a professional situation.