I seem to remember back in high school experiencing some pressure to "put out," if you know what I mean. (Remember, we're talking the EARLY sixties, here.) Having been raised in God-fearing Catholic homes, and having had 12 years of C.C.D. (Confraternity of Christin Doctrine) classes pounded into our heads, my close girlfriends and I lived in fear of the wrath of God if we failed to be anything but "pure in heart, word, thought, and deed!"
Such circumstances required creativity on the part of said boys. It was not unusual if a boy were to get to the point of passionate kisses with a girl (and maybe slipping her a little tongue), for him to push for more intimate favors. Logical arguments would be presented; "other girls are doing it;" "if you really loved me, you would," and when all else failed, horror stories of great pain caused by bloated testicles
which could become discolored.
Maybe there really is some truth to the term "blue balls."