re: How do you get a girl with a boyfriend?

It's obvious that this situation is the women's version of "why buy the cow when you can get the milk for free?".

Why would she have to make hard relationship/life choices when you are giving her all of the emotional support that she wants?

If you want to frick her.... just do it. She's already decided whether she would or wouldn't frick you.

If you want a relationship, it is a bit more complicated, but one part is clear.
You should make your intentions known and quit being the emotional support.
Make her make a decision. She will break up with her boyfriend if she truly prefers you.

Either way.... it will work out best for you this way.