Couple workouts?

Janelle
How can my boyfriend and I motivate one another to eat better & exercise? If one of us gives in, we usually both fall. I have the benefit of having another person along with me to help me on this journey but this person isn't helpful when he decides to erratically purchase fries and a burger for lunch while I'm starving for dear life! Any tricks or tips that we can try to help trick ourselves into creating a better lifestyle?