JohnT:
At some point activity will inevitably stop though. My now wife was in the 200s ten years ago and quit mobile, agile and fit. She has been steadily gaining over the years- something I discreetly encouraged - until almost 5 years ago when I confessed to her that I am a feeder and that was the turning point of her massive gain. She is now 593lbs and although not immobile, she’s hardly mobile. Even though we were happy in a relationship as a girlfriend and boyfriend, i wanted her to feel secure in this new condition.. that i will always take care of her and be there for her regardless of her massiveness and immobility, so we got married a few months ago. I love how she let go, and I can’t wait to see her hitting 600 and beyond even if it means that we can’t do together all these activities normal young couples do. I love driving her around and going out to restaurants that have accessible seating for her. Or pushing her wheelchair when we go to malls.
True at a certain point your mobility will almost entirely be reduced. But exercising and staying active will help you stay mobile longer which should really be the goal. I know immobility is a fairly common fetish on here, hell i'd be lying if I said the thought of being that size never crossed my mind. But if you read any posts on here from people who are immobile, they're talking about how they are trying to lose weight or wish they could lose weight.
Immobility takes a toll on both your mind and your body, and mobility aids won't work forever. Not all cars are accessible for plus sized people, not all restaurants have accessible seating, and mobility devices have weight limits and the ones that don't have other problems. I just assembled a power wheelchair at work yesterday for a patient who's nearly 400 lbs, and the chair was 35 inches wide and too big to fit through most doorways.
As a feeder you should be helping your wife stay as active and mobile as possible. You two may not be feeling the effects of it yet, but eventually it'll catch up with you