Would it be fun getting in shape with my girlfriend? Is it a good idea?

We both have talked about trying a kick boxing class together or something else to get in shape. She has abit of a stomach and am skinny as hell so i wanna ganna 80 pounds while getting in shape while she just wants to lose her stomach. So would it be fun doing it together?
Would it be fun getting in shape with my girlfriend? Is it a good idea?
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