Two general thoughts:
Men like it better when it's their idea (sorry boys, but several gf's concur).
You can't make anyone do something they don't want to do, ie. you can't convince someone to lose weight/quit drinking/quit smoking/exercise until they are ready to do it for themselves. My sis keeps trying to push my cuz into exercise. I keep telling her to back off--let her know how much fun we have and we're here if she needs info or support. Otherwise, leave her alone. (We've changed our concept at family-get-togethers. Instead of begging others to join us, then canceling because we felt guilty--Now we go. You're welcome to join us, otherwise we'll be back in a couple hours. It's surprising how well this concept works.)
(Oh, and I think garage sale's are based on the concept that many fitness ideas don't stick!)
Don't let him ruin your fun
"Well-behaved women seldom make history." --Laurel Thatcher Ulrich
'09 Trek WSD 2.1 with a Brooks B-68 saddle
'11 Trek WSD Madone 5.2 with Brooks B-17