During puberty, you have lots of emotions and sexual feelings. It's normal for girls to think about girls in a sexual way, and for boys to think about boys in a sexual way.
Some people realise they prefer people of the opposite sex, while others feel they prefer people of the same sex. Some people realise they are gay, lesbian or bisexual at an early age, while others may not know until later in life.
Some young people may also be confused about their sexual identity. They may be asexual, where you're not interested in sex at all, or transsexual, where people believe there is a mismatch between their biological sex and identity as a boy or girl.
You don't choose your sexuality, it chooses you. Nobody knows what makes people gay, lesbian, bisexual or transsexual. Whatever your sexuality, you deserve to be with someone you love.
What if I'm gay, lesbian or bisexual?
It can help to talk to other people who are going through the same thing. Find out if there's a young men's or women's group in your area for lesbian, gay or bisexual people.
These groups might be advertised at GP surgeries, sexual health or contraceptive clinics, pharmacies, youth groups, local papers, or on the internet.
Find sexual health services, including contraceptive clinics, near you.
Should I tell anyone I think I'm gay, lesbian or bisexual?
This is up to you. Being gay, lesbian or bisexual is normal, but some people don't understand this. Telling people you're gay, lesbian or bisexual is known as "coming out".
Read about coming out and find out about the things to consider before you decide whether to tell people.
What about sex if I'm gay, lesbian or bisexual?
We all have the same feelings and anxieties about sex. Deciding when you're ready to have sex is a big step, whatever your sexuality and whoever your potential partner might be.
Everyone is ready at different times, but don't have sex just because your mates or your boyfriend or girlfriend are pressuring you. Find out about dealing with peer pressure and why it's OK to say no.
You can also read Are you ready for sex? to find out 10 things to ask yourself if you're thinking about having sex.
If you think the time is right, talk to your partner about needing to use contraception, having safer sex, picking the right time, and how you would both like the experience to be.
STIs with someone of the same sex
If you're having sex with someone of the same sex, there's no risk of pregnancy, but sexually transmitted infections (STIs) can pass from girls to girls and boys to boys, as well as between girls and boys.
If you're using sex toys, cover them with a condom and use a new condom every time – condoms should only be used once. Boys should always wear a condom if they have oral or anal sex.
Make sure you know about all the methods of contraception, whether you have sex with males or females, in case you also have straight sex. It's better to be prepared with contraception than to put yourself at risk. Always use condoms to prevent STIs.
How to get free condoms
You can get free condoms from a sexual health, community contraceptive or young persons' clinic and some GPs, even if you're under 16. Find your nearest clinic.
You can also buy condoms from pharmacies and supermarkets. Remember, only use condoms with the CE mark or the BSI kite mark. This means they've been tested to high safety standards. Condoms without the CE mark or BSI kite mark aren't safe, so don't use them.
How to cope if you're bullied for being gay
Some people don't understand that being gay, lesbian or bisexual is normal. Nobody has the right to tell someone else how to live their life or pick on them because of who they're attracted to.
If someone bullies you because you're gay, lesbian or bisexual, it's their problem, not yours, and they shouldn't get away with it. This is called homophobic bullying.
Bullying can take many forms, including stares, looks, whispers, threats and violence. If you're being bullied because you're gay, lesbian or bisexual, tell someone you trust. This could be a teacher, friend, your parents, or a helpline.
Schools have a legal duty to ensure homophobic bullying is dealt with. Read about where to find help if you've been bullied for advice.
You'll find information about talking to teachers and parents, and the contact details of anti-bullying organisations and helplines. Talking to someone who is understanding will always help if you have worries or questions as you'll feel supported and more confident.
You can find out more about dealing with homophobic bullying on these websites:
EACH: Educational Action Challenging Homophobia
This is a charity for young people and adults affected by homophobia. It has a helpline for young people, parents or teachers who want to report homophobic bullying. Call the EACH actionline on 0808 1000 143 on weekdays, 9am to 5pm. Calls are free from landlines and most mobiles.
Stonewall: Education for All
Stonewall is a charity that campaigns for equal rights for lesbians, gay men and bisexual people. Its Education for All campaign tackles homophobia and homophobic bullying in schools across the UK. You can find case studies, facts and figures about homophobic bullying in schools, and advice for young people and teachers on the charity's website.