Definitely the penises. I mean, multiple orgasms, anyone?
Also, who would want to deal with a period on your FACE??? The only thing a forehead vagina would be good for is I'd probably tweet something/make a tumblr post about it with a gif of Dan Howell (danisnotonfire) saying "So... does that mean Zeus has, like, a birthing area on his forehead?" from that one Phil is not on fire video and maybe I'd be famous as that one person with a vagina on her forehead. IDK. My brain's weird.
Literal mind fuck
Also, who would want to deal with a period on your FACE??? The only thing a forehead vagina would be good for is I'd probably tweet something/make a tumblr post about it with a gif of Dan Howell (danisnotonfire) saying "So... does that mean Zeus has, like, a birthing area on his forehead?" from that one Phil is not on fire video and maybe I'd be famous as that one person with a vagina on her forehead. IDK. My brain's weird.