Am I cheating or flirting??? Please help?

Ok so I have the best boyfriend in the world and I love him a whole lot and he loves me too. Now "naturally flirting" runs in my family and I think I may have it too. You see with guys I act different around them than with my girl friends. I dont like compliment them or stare at them but I just act a little different. I dont twirl my hair or whatever or stick my out lol....but this is the way I have always acted around guys. I try to be funnier and make them like me without doing anything wrong. Like I dont care if they dont like me its just I will always talk to guys differently. Is this naturally flirting? And its only with guys like i act a little bit different with guys. Am I cheating on my boyfriend or flirting? am i a natural flirt? is flirting cheating? please help i would never wnat to hurt my bf also wats ur definition of flirting?