A 14 year old is extremely impressionable and can't really understand the subtext in conversations and actions all that well. If a man that has significantly more life experience than her comes into her life, wanting to be her partner, aka becoming a larger part of her life than he is taking advantage of her naivety.
Allowing this kind of behavior is what leads to cunning manipulators like Onision to show up into the lives of young people, being as charismatic and charming as possible in order to win them over. Why someone like Adrienne, who was the same age as Greg, was able to see past his deceit but Shiloh couldn't, because she was too young to see all the red flags around her.
If this doesn't convince you that your line of thought is a bad idea than please do this autistic forum a favor and never reproduce.