Sweetness is a playful affectionate name for someone close to you. Sweetness plays off the terms sweet (cool/awesome) and sweety (loving/caring person).
There is a specific way to say sweetness. You must always nod your head (as if saying hello), along with an elongated blink of the eyes, while pouting out your lips slightly. Always proceed with a tight hug afterwards. Sweetness is a powerful verbal aphrodisiac and should be used sparingly!
It can be used in two ways.
1. It can be used in a sexy manner towards someone you find sexually alluring.
2. It can be used in a playful manner towards a close friend.
Generally used when someone wants to express extreme joy. Nerds often use this word after watching Star Wars, hacking into a difficult database, watching "American Beauty" with out their mom catching them or when they feel like being cool.