If you live in Victoria this is what the law says with regards to when you're allowed to have sex:
As far as the law is concerned, sex is not just having sex but someone touching you sexually and also performing a sex act in front of you. It also means sex between two men, two women, one man and one woman, or any other combination you can think of.
When is sex not OK, regardless of age?
When you or the other person do not agree to have sex, this is called 'consent'. Everyone has to agree to have sex, and should want to have sex. Sex should be fun, pleasurable, and rewarding for everyone involved without any exception.
No one should be forced to have sex or to do something they are not comfortable or ready to do. You have the right to say no, and to refuse to do anything that will make you upset, embarrassed, ashamed, feel hurt or pain, anguish or any other negative emotion.
If, and when, you say no your decision has to be respected and sex has to stop. If it continues despite you not wanting it this is illegal.
Anyone who agrees to have sex has to not be pressured to agree and has to be free to make that decision. Someone who is very drunk or under the influence of drugs is not considered to have agreed to sex, even if they had said they wanted to.
Also, someone who feels intimidated or overpowered to agree to have sex is not necessarily considered to have made that choice freely under the law!
Under 12 years old
If you are under 12 years old no one is allowed to have sex with you and you are not allowed to have sex with anyone under any circumstances even if you agree.
13 to 15 year olds
If you are between 13 and 15 years old then you can have sex as long as the person you are having sex with is no more than two years older or younger than you. That's two full years, not one and a half years, or almost two years, not a year and 364 days, two years means just that, two years.
Sixteen to 17 year olds.
If you are sixteen or seventeen you can have sex with most people, except anyone who is looking after you like a teacher, a youth worker, a counsellor, or a doctor.