Dear Sexpert,
I drink and sometimes I black out. Recently I've started to wonder whether I've had sex with anyone the night before, but I just can't remember. Is there anyway to tell if you've had sex when you've blacked out?
— Nervous
Dear Nervous,
I understand your concern and I know how scary it can be to wake up one morning unable to remember what happened the night before. That said, if you know who you spent the night with the best way to find out whether you've had sex is to ask the person. If you wake up with someone else in bed with you (or something to that effect), roll over and ask what happened. Or if you have friends who were with you that night who can remember what happened, feel free to ask them as well.
If you are at all concerned that you may be pregnant as a result of what happened the night before consider taking emergency contraception, also known as the morning-after pill or Plan B, if you are comfortable with that idea. As you may know it is now available over the counter for those who are 18 and over; you can walk into a pharmacy without a prescription to get it. If you're under 18, however, you still need to have a prescription.
If what you've brought up here is a big concern, you should seriously consider cutting back on your drinking so that you are still able to remember the events from the night before. You can arrange to have at least one friend who is willing to watch over you while you're drunk. Make sure he or she knows what you are and are not comfortable doing and is willing to prevent you from getting involved in something you know you'll regret.
— The Sexpert
Dear Sexpert,
What's a dental dam?
— Dam it
Dear Dam it,
A dental dam is a rectangular piece of latex. It has a few uses, but I'm guessing you're not asking about what dentists actually use it for. A dental dam can also be placed over the vagina and the anus during oral sex to protect against STIs. For those with latex allergies, there are dental dams made of other materials. There are also flavored dental dams available.
You can create a makeshift dental dam by cutting the tip off a condom and cutting it down one side so that it forms a triangle. You can also cut a rectangle out of a latex glove. You can even use a piece of plastic wrap. Just make sure not to use the microwaveable kind because it has holes in it.
Just like a condom, a dental dam should not be used more than once. Don't flip it over and use the other side because you'll come into contact with anything that was on the body. Don't move it from anus to vagina or the other way around, either, because one can contaminate the other. For the same reasons, don't use it on one partner and then on another. These things are definitely one time use only.

You can get dental dams on campus by going to the LGBT center located on the second floor of Frist Campus Center.
— The Sexpert
"Ask the Sexpert" is written by a team of peer sexual health educators and fact-checked by University health professionals. Submit questions, to be published anonymously every Thursday, to sexpert@dailyprincetonian.com. Don't be shy!