Most Helpful Guys
Depends - usually cleavage, but if the underboob is from a loose- fitting, very high-cropped shirt that barely covers the nipples and shows basically everything, that's hotter1
Because when it is a good one, it reveals boobs when you bend ahead.
Underboob is really sexy nevetheless. 😉1
Most Helpful Girl
Cleavage is hot underboob is tacky.2