Weeell, ENFPs are just nice people. For example: a girl is cold? The ENFP gives her his coat. Does he like her? Who knows? He was being nice. What about needing a ride home? "Hey, I haz car! Come with me!" Are you sick? The ENFP will call you to see if you're okay. Can't find something to do on Saturday? "Come with me and my buddies!"
...Basically, ENFPs seem like flirts because they treat most people wonderfully. In my pleasant experience.