A threesome, yu migh not want

I was watching this show today on TLC called Joined For Life: Abby and Brittany Turn 16 . These girls are joined together, as yu can see below, they share a lot of body parts, but have two ribs, and a heart.. The girls just turned 16 and I'm sure they've been through enough things together. I couldn't imagine having another head on my body, like...my main question was how would they have sex? What if one likes a guy, and the other doesn't? What if one's a hoe, and one's not? They both get the benifit, but one isn't a hoe?...or wait, how do they move each leg?