Cherie, why break up mean being an ass meh?
Everyone have the right to pursue their happiness. If she is not happy with this man and want to pursue happiness elsewhere, does that make her the villian? The need to find something or one to blame is actually really childish. Both are adults, should handle relationships more sensibly mah.
For sure, there will be hurt. But, not suitable, means not suitable. Relationships cannot force one. It takes 2 to tango.