Hey Cyn, seriously, congrats on your healthy lifestyle. It's amazing how much it can extend your life expectancy!
I also used to really hate sweating - I suggest SWIMMING!!! It's fun and you can do a lot of different strokes (she can rock the kickboard for the first week, even) and it's a really great low-impact exercise so you don't wear down your joints (like running can if you are obese). If you have a good pool near you, you can share a lap lane and even keep up conversation while you're working out. Water aerobics are also fine. You can get a workout just treading water in the deep end and splashing around.
I'd bite the bullet and start working out together. If you just continue to sit around and lose weight from dieting while she's not, she might get more bummed out about failing as you succeed and is less likely to do something about it. If you exercise together, it will seem like less of a punishment and more of a mutual lifestyle change.
Plus, you really DO feel better - more energy, good sex drive, lower appetite and all around good vibes about yourself. You can start slow with a walk after dinner, a game of badminton and then GO TO THE POOL! Just make it fun.
Good luck - let us know how it goes!
P.S. Sweet new gear always motivates me - a new pair of running shoes, a new swimsuit, flippers.. (they are FUN and a good workout) - it's like you spend money on something that will move you to be healthier and you can't wait to use it!