Cute co-worker has a boyfriend and keeps flirting with me. Apparently she's very smitten. I'm a bit annoyed by it given the fact I don't like flirting if there's no possibility of a future; she's in a relationship, off limits. If she were single that would be another story entirely. Also, she keeps texting me but for some reason she doesn't like to continue the conversation, it just trickles off.

Someone tell me what to think, because I'm pretty confused in this scenario. I have no precedent for it.