In general I would say stay away from any relationship with a client, do you know if he is single? Even if he says he is, it's more than likely he has a family. Have you talked to him much to get to know the real man? We and clients often put on a punting personality?
If you really want to see him again and feel you know a little about the real person, talk to him, maybe meet for a coffee, could you meet somewhere half way between where you live. Maybe go for a coffee and make it clear you are meting for a get to know you chat and no sex will be on offer. Maybe even take it off the menu for a few dates if things do porgress, this will make it clear if he wants you for sex (sorry to be blunt) or wanting to get to know you.