I wear black slips as skirts on a semi-regular basis with tights and a longish top. I don't find it all that offensive, I'm covered and everything. I do laugh at the irony of our generation, wearing it on the outside instead of something to be hidden. Although I think it has a bit more class than the "look it's my bra" trend.
There is a shop here in Seattle called Pretty Parlor that makes cute slips alongside their reworked vintage pieces!