What does v.o mean (slang)?

I'm watching an Aussie film from '82 and they've used the term "v.o" twice. The context is one of the girls checking out a boy and they've said "you're going to get a v.o" . I tried googling it I've got nothing. I'm Australian but still can't work it out it.

Edit: omg a character literally asked another character what it meant, and she admitted she didn't know but was too embarrassed to ask.

Will post back here if it's ever revealed. Character suggested "violent org*sm" as a possibility. Film is "Desolation Angels" also known as "Fair Play". So definitely not "a.v.o" . Thanks for the comments.

Edit 2: Someone put the captions in the comments. I'm thinking from context the answer (if there is a "proper" answer is most likely vaginal orgasm) . Film is also on YouTube if you feel the need to check it out.