She's single because she refuses to change her relationship status for someone who falls short of what she deserves. Knowing her self value, she's chosen to preserve a spot in her heart for a real man, someone mature enough to understand that loyalty, commitment and honesty is a priority and not an option.
Also on these boards
A Real man to me is an alpha male who is R.E.A.L. Raw Empathetic Accepting Loving Michael, you are a REAL man, I thank you for showing me what was possible.