My company has 3 owners/employees: me, my best friend and my dad. When we play golf together we'd love to expense it as business specially since half of what we talk about IS business. I know from personal experience though that it's just a sure fire way to get audited.
So if you're taking clients or business partners / execs from other companies out to play golf, can you expense that? I know if you take them out to eat and expense it, it's acceptable. Mountain biking sounds a little ridiculous but where exactly is the line drawn?