"T-bag" reffers to the scrotum. "T-bagging" oringanally meant putting ones scrotum into someones mouth while they are asleep. The term "T-bagging" is popular from the game "Halo" and it refers to a movement that the character makes by kneeling down over the head of a dead opponent.
When you take your man pouch and move it across an enemy's pillow when he's away. When he falls asleep his face will have been on where your business has lied. The number can be replaced with how ever many hours the victim sleeps.
Man: "I was so angry with Steve last night that while he went downstairs, I gave him the ten-hour t-bag."
A whore that is infected with a large quantity of STDs and then sleeps with tons of people, infecting them. This effect is similar to when a tea bag is placed in water. The tea spreads throughout the water.