I think...
If its only a few days, the guest should (sincerely) offer to pitch in, and the host has option to refuse.
if it is weeks - pay up or they better be fuckin' me - if they want the free ride. If not they can expect some quick termination of the present verbal agreement (family relations and my best of friends are excluded from this rule)
__________________
believe me - without free porn, just as many people will seek porn out on the Internet, and many more will pay if there is no free alternative, its not like sex is a fad - it can be milked much like any renewable resource - long term
i wasn't born with enough middle fingers
- Marilyn Manson