Turn Signal Fuse Shorting Out in Reverse

So the turn signals on my automatic '96 Sunfire SE (2.2L) stopped working the other night. We figured it was a blown fuse, replaced it, tried the turn signal in park, and YAY! it worked again. Of course, that was too good to be true because I go to drive it today and hmm, no signals. So we replaced the fuse again, only with the car in drive, and it worked fine. However, as soon as I shifted into reverse, the fuse blew again. The fuse keeps blowing as soon as it hits reverse -- any ideas as to why would be GREATLY appreciated.