Is it worth getting involved with a girl who has a boyfriend?

Sad to say this, but she's pretty much the first girl who has ever shown interest in me. She thinks I'm so funny, has that "gleam" when she sees me, invites me to eat, hang out with her friends. But then I was so unsure of the whole situation that I distanced myself from her. Now I haven't really talked to her in 3 or 4 weeks though she's said "hi", "bye" and still smiles and all that stuff in that time.

So now I feel like I kind of ruined my opportunity by not doing anything/making a move in these three/four weeks; then again, she has a boyfriend and this could all be in my head. But also, then again, if her interest is real, I don't want to ruin it, though I may have already.
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+1 y
ok, she's finally single now. apparently she had that boyfriend for a long time.
Is it worth getting involved with a girl who has a boyfriend?
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