It's much smarter to talk about condoms before having sex, but that doesn't make it easy. Some people — even those who are already having sex — are embarrassed by the topic of condoms. But not talking about condoms affects a person's safety. Using condoms properly every time is the best protection against sexually transmitted infections (STIs — even if you're using another form of birth control like the Pill.
So how can you overcome your embarrassment about talking about condoms? Well, for starters it can help to know what a condom looks like, how it works, and what it's like to handle one. Buy a box of condoms so you can familiarize yourself.
The next thing to get comfortable with is bringing up the topic of condoms with a partner. Practice opening lines. If you think your partner will object, work out your response ahead of time. Here are some possibilities:
Your partner says: "It puts me right out of the mood."
Say that having unsafe sex puts you right out of the mood. Permanently.
Your partner says: "Are you nervous about catching something?"
The natural response: "Sometimes people don't even know when they have infections, so it's better to be safe."
Your partner says: "I won't enjoy sex if we use a condom."
Say you can't enjoy sex unless it's safe.
After you've familiarized yourself with condoms and practiced your routine, you'll want to pick the right time to bring up the subject with your partner. A good time to do this is long before you're in a situation where you might need a condom. When people are caught up in the heat of the moment, they may find they're more likely to be pressured into doing something they regret later.
Make it clear that you won't have sex without a condom. If someone threatens you or says they'd rather break up than wear a condom, it's time for you to say good-bye. Tell the person you won't have sex with someone who doesn't respect you or themselves enough to use protection.
Reprinted from http://kidshealth.org/teen/sexual_health