You call it " raining on the parade," but it's a reality check. If you go to the office Halloween party every year dressed as a female with a nice, well fitting wig, good breast forms, padded panties, well fitting clothes and heels, perfect makeup and walk around in heels like a pro, the folks will figure out that you don't just do this once a year for the party. Think about it.
Now if you can go where people don't know you, that's fine. If you pass, you pass. If you don't, well it must be a Halloween costume then. Find a club that's having a costume party and go there. Or just go to the bar district.