Just my personal opinion, there are guys who are into the hunt, other guys are more homebodies/relationship types. For a "hunter" the chase is almost as much fun (sometimes more) than the "kill" and the game stops being half as fun once the goal is achieved
I'd suspect the one way to keep a "hunter" interested is to keep some mystery/surprise and consider incorporating role playing games (y'know, you dress different, wear a wig and meet at a bar, shit like that).
Frankly, I think it's easier to find a homebody type who likes routine