Help - my bf is making me overweight

So before I met my bf, I competed in 2 triathlons a year. I was by no means perfect, but I had a good body and trained. 5/6 days a week.2 years ago, I met my bf. He's perfect in many ways. We recently moved together and things have changed. Of course over the past 2 years, I'm not training as much, because he doesn't like to exercise so we do other stuff.When we didn't live together, I would go on nights I didn't see him. Now he wants me home after work and questions me on the few nights I've wanted to hit the gym.I don't need a perfect body, but I do want my clothes to fit. I recently checked the scale and freaked out. I've been 165 for most of my adult life, and now I just hit 200 pounds. i knew my clothes were fitting tight, but this isn't me.I feel like a prisoner, because I really can't leave my job during the day, but haven't started sneaking away to hit the gym for a bit. I don't want to lie to my boss or my bf, but feel like I'm going to say something I regret if I don't let him know I want to exercise.In case you're wondering. He's overweight and has no interest in the gym or fitness. Help what do I do?