It has got alot to do with how you approach friends and treat
them.
You might be in the category of a fling/sex partner/non gf
material.
Usually, my observation was - friendlier girls are more prone to
became flig materials.
Interestingly, as the same time, they couldn't help it but to get
involved to this kinda of guys again and again although they didn't
want it.
Cheers