I'm fairly new, but I have little problem opening in bars, clubs or out in the streets in between. However I still have some real AFC moments in the day. I think I can work on these except for the situation of being at work.
My office has a few HB7-9s, some with BFs, some single. There's a HB7.5 on the ground floor who sits only next to one guy and I never used to speak to her until early on in my PUA days (still under a month ago) when I realised I'd no reason for AA. So I opened with some stuff about work before talking about my impending holiday in the far-east (possible DHV?) when she turned her chair around, moved closer and opened her body towards me with one hand in her hair. Inside I was like

if that wasn't an IOI... I wrapped up the convo and as I was leaving she was still trying to talk to me.
I've been down to speak to her once since, had a similar convo plus a neg, and had pretty much the same reaction.
Three issues, with this and general office PU:
1) If this was a bar, you'd try kino or at least #-close. In the cold light of day, I'm worried about the audience (despite it being small, although rumours could go round) knowing we're attracted .
2) I don't know if she actually is single, and still have never really known a good way of finding out
3) If things don't work out, we'll see each other quite a lot compared to chicks who work elsewhere.
Any advice or opinions?