Well a girlfriend of mine just found out that a guy she was conversating with is actually dating someone, now of course when she told me this, the first thing i thought was did you ever ask him was he dating anyone at all. She did say that she asked him did he have a girlfriend, and he responded no, but we all know all to well that with men you have to be specific because he was telling the truth that he didn't have a girlfriend, but he didn't care to expose that he was also dating.
What i have found out in my adult years about men is they have their own code: If you don't ask i won't tell, or better yet if you don't ask i won't volunteer.
So my personal opinion is for women when you are out here dating or trying to find a perspective mate, always take the time to see what's really going on, when you ask if he has a girlfriend make sure he isn't dating either! 2010 ladies don't be deceived.