I agree with what the majority of what everyone else has said (always tell someone, don't do what you're uncomfortable with,etc). Additionally, I would report it to Rover Support. They have investigators who look into the validity of someone's account. Other people may get requests from him and not pick up on his strange behavior (repeated rescheduling/excuses) and comments (living in his car). It is important to look out for yourself, but as part of a community it is also important to speak up when something doesn't seem or feel right. It's always better to be safe than sorry.