Is it important to take advantage of any opportunity to practice seduction? If there are any valid excuses to avoid it, what are they?

For instance, there’s a girl I sit beside at work who is absolutely gorgeous. But she is also in a LDR. We are friendly and make small talk, socialize in the same circles, etc. But I don’t go out of my way to speak to her, and I feel like she kinda resents it (even though all conversations have been initiated by me). But I also kinda resent myself, because it’s like…what am I doing?

I have this drop-dead gorgeous chick right beside me every day with no one to talk to. And I’m not building rapport every second I can half out of social anxiety and half out of not wanting to be too pushy with a woman in a relationship. Crazy thing is, I really believe I could pull this chick if I put my mind to it (which would be scummy obviously).

But that goes back to my original question: should I be pursuing all golden opportunities? Is there ever a good excuse not to that doesn’t sound like bitching out?