As a long-time lurker to this thread (and GAF), I thought I'd throw in my scenario and see what y'all think...
There's a beautiful co-worker whom I'd like to ask out, but I'm having difficulty determining her interest level. We started chatting in the early spring, and since then, I have made it a point to escalate our communication so I could have an "excuse" to talk to her more often (e.g. transitioning from small-talk, to e-mail, to IM-chats, and, eventually, texts -- all when in-person communication is not possible). We follow one another on Instagram (I do some amateur photography on the side) and she saw that I had been visiting various parts of the city. During an e-mail exchange, she offers her cell number to me and says that if I ever want some company during my cityscape explorations, I should let her know.
"Awesome," I say to myself. "This is a great sign -- clear and unambiguous."
A few days later, I ask her over text if she wants to join me for an excursion downtown, but she politely declines and, perhaps tellingly, doesn't offer an alternative date to hang out (which I now interpret as a bad sign). I note this as a red flag, but it's still early so I just let her rebuff go...
A few weeks go by and we resume texting/flirting. The following day at work, over IM, she asks me out to lunch and we set something up for mid-week. At lunch, I note that she reveals to me that she's "very shy." I would have never known her to be shy because she seems very friendly to pretty much everyone around the office (we all know those types of seemingly extroverted girls like that, right?). Anyway, her revelation about being shy is a geniune surprise to me...
...I think she was trying to tell me something when she revealed her shyness (i.e. "Ask me out"), however, I'm not getting any other instances of interest from her. For example, there's no non-sexual physical contact (i.e. she hasn't touched my forearm or something like that during conversation). She also sometimes curtails her texting/IMs rather abruptly, and she almost never initiates a conversation.
Most recently, as she's spent a lot of time moving into her own place in early July -- along with summer travel for both of us -- our communication has been minimal and I sense that if there was an attraction from her towards me, it is now petering out before anything can even start.
The last "mixed message" event occurred about 10 days ago, where, following a company summer party, we started IM-ing and talked about our experience at the party. She said that while she had fun, she was exhausted from the whole thing, citing that she was an "outgoing introvert" (as an introvert myself, I find that hard to believe because she was working the room quite well, while I find going out into large groups as anxiety-inducing). Anyway, I teased her about being an "outgoing introvert" and over IM, she sends me one of those cheeseball Buzzfeed-like articles about "What You Should Know Before Dating an Outgoing Introvert." I can't tell if that was an innocent link she sent me, or, again, if she was trying to (shyly) tell me something...
My assessment is to treat perceived mixed messages as a red light and to not pursue. For my money, getting into emotional knots over mixed messages is not healthy and I've often disengaged from those situations.
That said, I'd be curious as to anyone else's insights in this thread -- whether they have had similar scenarios, and what they did/did not do in those scenarios.
Thanks for taking the time to read this long post!