Jeans Spandex Disco Spandex Disco Jeans?

Spandex disco jeans? - jeans spandex disco

My friend and I had a ridiculous argument about fashion 70's, one of the issues that arose were extremely tight jeans and bright spandex, these bags on their backs and had a front zipper.

He said, because they, before the invention of the tape, used these pants without underwear. This question is for those who have used them as in May

Was it spent on these things? Or were just below the waist clothing?

How did you come to the conclusion that they like and how do you feel the first time you use them to celebrate?