Hi, i also have this problem for more than ten years, i am married and have two kids also.for sure it is not torsion of testis as it is very painful and when it happens you cant even move your leg and the scrotum
will become swollen and red.
i had this tightness sensation when i was around 18 years, the scrotum used to come so close to my belly that i hardly notice there is any scrotum. in winter after the bath my scrotum used to be very close to my body. i did not tell this any body, it is very embracing to discus this with friends.
one of my friend got into medicine and slowly i asked him about the scrotum tightness, he said it is ok not to worry as such and it is because of short scrotum skin. unless there is no problem with sex or there is no pain you need not worry.
one more thing the tight scrotum has some protective effect against the torsion of testis