No it doesn't mean that unless your question was more directed towards when you're just having sex. When a man's genitals are cold they tighten up and the skin thickens to keep them warm, and they do the same when a guy is tense. But if it warm down there they get very loose so they can cool down. LIke some others said, so that the spermies can maintain as close as possible to the same temperature. Yeah, they probably were given a mind of their own. lol!
If its cool in the room, testes get closer to the body to warm up, If its hot they move further away. They have to maintain a temperature in the upper 60s for good sperm production. That's why they are not located inside the body, like all your ladies plumbing is.
it has to do with the thermal regulation of the testes, which work better at a slightly cooler temperature than the rest of the body. The balls do retract a bit during ejaculation but don't stay that way long.
Temperature of the room determines this. Warm air makes them hang lower and cooler air makes them tighten up because the sperm cells need to be about 4 degrees cooler than body temperature for them to live. That's why the testes are outside the body instead of inside. It's strictly a temperature regulating thing, like a thermostat.
Actually it may mean he ejaculated if they go from saggy to tight. I get sagging balls too, but there's a supplement I have taken and recently started a web site for that stops my sagging. Check it out at somalabexperiment.com
The sac protects his balls and the balls are temperature sensitive. When that area of a guy is really warm the sac is loose (longer and sagging) If the area is cool the sac retracts to help keep the balls warm. A mans sperm is in the balls and temp is critical to keeping the little guys alive and squirming.