Trying to flirt can certainly be interpreted as harassing in the wrong context. If someone has never so much as said anything to you that wasn't strictly work-r

Trying to flirt can certainly be interpreted as harassing in the wrong context. If someone has never so much as said anything to you that wasn't strictly work-related or banal small talk, flirting with them is not likely to go over well. In a different situation, where you and this person have been chatting, bantering about silly things, etc., they might be open to casual flirtation, since it's now not just coming out of left field... and you could still be wrong about how it will be received. Been there, done that, apologized immediately and we both moved on from it to stay friends. But that's the difference: realizing that you did something unwelcome and genuinely apologizing for it. Most reasonable people will be accepting of that behavior.