The problem is that all girls seem to already boyfriends....
SO approach her and ignore it. It is that simple, I have done that so many times.
"But I have a boyfriend."
Take your Pick:
"So do I, do you want some of this"
"Oh thats nice but he is not invited"
"Thats your problem not mine"
It does not matter how long they have been together.
A few months ago I had this happen with a particularly beautiful girl. She talked to me for a few days and I had my hands on her and kissed her lightly and told her I wanted her. All after that she said that she had a boyfriend and my reply was "So what, what does that have to do with anything?" It was obvious she was already into me. I ignored her for a few days and when I saw her again, she was eager to tell me that her boyfriend had left her (she was lying, she left him I am sure). Now she is the love of my life. (and so is any other woman who I can convince)
The bottom line is women have no common sense, intelligence or strength. If you get their hormones running, they will do what you want and you wont have to have one of those so called "relationships" I keep hearing about.
Youre not trying to get married or to have a "meaningful relationship" so who cares? Lie to the bitches. Dont play their games.