Oops!
So as of 2:30 this afternoon (about 3/4 through my workday) I was standing in the bathroom at work and noticed something didn't look right. I stared a little harder at my reflection and realied that the top I was wearing is translucent.
It isn't immediately apparent - I didn't see it when I put the shirt on, nor did I see it when I look down - but once I noticed it became totally obvious. Especially in the glare of the bathroom lights.
Luckily it was chilly this morning, so I'd brought a jacket with me. Still, how embarrassing!