My boyfriend and I were having sex the other night. He wanted to try anal sex. I've never had anal sex and I wasn't sure about it, but he put his penis into my anus and he only got it a little bit, but couldn't go more than halfway. After a while I told him we would need lubrication. But we didn't have any. Then he stuck his penis back into my vagina. I told him he should have washed off first. It's been four days and I have smelly discharge and it burns a lot. I suppose I have an infection or something from what he did?

YES, I'd bet dollars to donuts that you have a vaginal infection!

The anus is full of fecal germs! Many of those germs are infectious. It doesn't take complete penetration to put your fecal germs onto his penis. Yes, it's gross, but tiny fecal particles got deposited into your vagina when he put his penis back into your vagina. Bacteria from your feces then took hold and multiplied in your vagina, resulting in bacterial infection.

First things first, you need to abstain from sexual activity until you cure that infection. See a doctor right away, and do not try to treat it yourself. You cannot resume sexual relations until you are totally treated. You also should not use vaginal douche or tampons. Doing any of these things can aggravate a vaginal infection.

Secondly, you and your boyfriend need to learn (and use) some safety practices.

1. You need to use condoms during anal sex. And you need to slather that condom with condom-safe lubricant. The anus does not lubricate itself and it's very delicate. Using condoms and lube are VERY important for preventing injury. Moreover, because the anus is a sphincter (meaning it tries to keep itself closed), you might want to ease into anal penetration by starting with smaller things like fingers or slim toys with a flared base.

2. You never insert anything into your vagina that has previously been in your anus/rectum unless it has been totally sanitized first. Are you familiar with the term cross-contamination? That means you take germs from one place and transfer them somewhere else, possibly resulting in sickness. Much like you shouldn't chop raw meat on the same surface as you cut raw veggies, you shouldn't put things that have been in other orifices (mouth, anus, someone else's vagina) into your vagina.

3. You can enjoy both anal and vaginal sex in the same sexual encounter, but your partner must wear a condom at all times, and change that condom when changing between anal and vaginal sex.

Read up on safety with these articles:

• Safe, Sound & Sexy: A Safer Sex How-To
• Condom Basics: A User's Manual
• The STI Files: Bacterial Vaginosis