Yes, there are SPs that I wouldn't need to hobby if they were my S.O.'s (they'd give me a reason to head straight home!).I'd stop hobbying if I married any woman I adored.
And like you say, SP or no SP, if I was in a happy relationship (I'm single), I don't think I'd hobby. I haven't been tested in that regard though.
I'm getting older. I don't need to sow my wild oats forever.