Damn. You've got a lot of faith in your man. That or you're very naive. Call me insecure, then. Ain't no way I'm letting "Hey sexy, whatever" go unchecked if I see it. Especially, if she does it in front of me.
Somethings, I like to reserve for one person. Flirty shit like that, I'd reserve for my woman. What do them other broads need to hear it for if I have no interest in them? Flirtation or any kind of sexual innuendo, That shit ain't to be thrown around loosely IMO. If I say some shit like, "hey sexy, heart, heart, heart", I'm trying to hit that. Ain't no other reason to put it out there like that.
But, I guess your dude would be different.