My dad did that too. He offered me money, trips, literally anything I wanted to stop lifting weights and lose muscle. I was like 255lbs at the time, probably like 18-20%. I hate to say it, but he was exhibiting very stereo typical Swedish narrow, hate anything outside of the box, thinking. At first I hated the harassment, but after a while I really started to love it; especially loved denying him by going and lifting again and again. 'It' created a huge rift between us, but in truth, HE created that rift and paid for it in full by f'ing up his relationship with his son for several years because of almost CONSTANT harassment and very hurtful remarks. Stick to it. Your parents are exhibiting, imo, some of the worst possible behavior imaginable, especially if you are clean and just doing this because you love doing it.