Husband vs Wife...a match up I didnt want.

Okay, so here we go, we are part of boot camp transformation challenge, we are about 6 weeks in of the 12 week challenge. My wife was the inspiration for getting into boot camping in the first place almost over a year ago. Tonight we had a meeting after doing MON thru THURS of pushing it to the limit. Ill admit I was tired but it was a good talk session, last session he had us go full tilt for 12 minutes to show ourselves how hard we should be pushing ourselves. fun stuff. Im enjoying the challenge and I find that Im really getting into it. My wieght had not started to go down until about two weeks ago, my wife, who is in good shape, has fallen off the wagon a couple of times. During the meeting, our instructor really pushed the WHY, you need to really know the WHY as to the reason or reasons we are doing this. We had a sit down and everyone discussed in short fashion what their WHY was. I was second to last, I spoke, said my wife was my inspiration and that I wanted to really do this for me, so I could participate in sports more, look better and feel better, came my wife's turn, she breaks down in tears and finally says the only reason she is doing the challenge is for me. So the instructor says, MAKE IT A COMPTETITION, SHE LOSES 10LBS TO HIS 20LBS, she has way less to lose than I do, but hey whatever. I didnt say anything but she did when we got home. I told her it might not be a good idea because I know how competitive she is and frankly, a sore loser...in anything. I tell her I dont think its the best idea and i dont want it to cause friction between us, she keeps saying, YOU ARE JUST THINKING OF THE TIME 10 YEARS AGO WHEN YOU WERE BEATING ME AT WEIGHT WATCHERS....yes and all those other games we played where she was bound and determined to be the winner. I compete for the sake of play, if I win then great, if I lose, then great, I got to play. My wife is a poor sportsman and beats herself up and down when she doesnt win and also rationalizes it with logic. personally, I dont care to listen to the bull****, so I recuse myself whenever I can or I listen patiently and try to present another side but whenever we hit the accountablilty area, forget it, it isnt happening. I know Im at fault but this, this and this happened. Point is, it happened. So my question to you ladies and gents, what can I do. I already had my say and needless to say, rather than listening, she pushed it off onto I would do better if we competed but you dont want to. My reply was why not just compete with yourself? Or find someone at work that is the same body type or just a good friend? Well, it is what it is. I agreed only not to get into an argument. I already know how this will play out but maybe someone can spot some good, other than wt loss.