There are various ways a dolphin has of showing that she or he is interested in sex. Males are probably the easiest to detect. They will swim around, sporting an erection (anywhere between 10 to 14 inches long for a Bottle-nose), and will have no bones about swimming up to you and placing their member within reach of your hand. If you are in the water, they may rub it along any part of your body, or wrap it around your wrist or ankle. (Dolphin males have a prehensile penis. They can wrap it around objects, and carry them as such.) Their belly will also be pinkish in colour, which also denotes sexual excitement.