There was a broken condom, but it broke prior to the sex:
Kenickie: Are you kidding?
[Sits up and gets a condom out of his wallet]
Kenickie: My 25-cent insurance policy.
Rizzo: Big spender!
[Kenickie opens the condom packet, is shocked as he finds it broken]
Rizzo: What?
Kenickie: It broke!
Rizzo: How could it break?
Kenickie: I bought it when I was in the seventh grade.
[the two spend a long nervous moment considering the situation, but look to each other with growing lust]
Rizzo: What the Hell…
[Rizzo grabs Kenickie, and they resume making out]
Kenickie: [muffled] Oh Betty…
From imdb.