Well, my girlfriend was tight, then as our relationship progressed, we got more physical. And eventually you "loosen" somewhat and it stops hurting to have sex.
No. Air tight means that no air can pass through and water may be able to, but water tight means that no water can pass through and air may be able to.
Why are your balls not in your body? There is an ideal temperature for sperm. It is a bit lower than your body temperature but also close to it. Your balls will tighten to get closer to the body for...