This may make me sound like a perv (I'm really not!) but if you have a closer look at the scene where Monica/Courteney takes off the bathrobe you can actually see a little of this (it think it's called Braza Bra or something)

Haha, I think we all have a closer look when watching that! I will definitely check again when watching the next time. And thanks a lot, I just googled it. Uh, let’s just say that this thing still doesn’t hide a lot. Lucky Matty.