With Marsha putting herself an inch from your mouth, you find it a bit hard to focus on sex. With just a little effort, she can be food...

Your hands grab her hips and adjust her a bit. Marsha is eager and helps you get her in the proper. Of course she thinks that is the best position for sex, not to be shoved into your already crowded belly, but she doesn't realize this is your goal, until you strike.

Suddenly you pull hard with both arms while lunging forward. Marsha folds like a blanket, her feet suddenly above her head, and her middle deep in your maw.

Marsha, once she gets over her shock yells for you to stop, but when you don't, she offers a deal "Eat me before you eat me. After I come good and hard, I'm your food."

A pretty good deal for you, if she is honest about it.