Dr. Brian Parker and I–a.k.a. Sex Doctors to the Rescue–were approached by The Charlatan, Carlton University’s student newspaper to answer some pressing sex questions their students had.

Here’s what I had to say on: how long should sex last, period sex, and whether to swallow.

How long should sex last?
There’s a belief that in order for a guy to be super studly, he needs to last all through the night. Definitely there are some guys and gals who would be on board.

Generally, for the majority of women, the closeness of intercourse feels nice, but it’s probably not getting her off. So going all night long will become monotonous and boring.

It’s important to know that for women, only about 33% of women will consistently have a vaginal orgasm. About 33% of women, when properly aroused, will sometimes have a vaginal orgasm. And approximately 33% of women will never have a vaginal orgasm. This is due to her “x” chromosome and no sexual technique can change how she is built.

This is especially true when there isn’t enough foreplay for her vagina to become sufficiently aroused. In fact, her natural lubrication will last for about 15 to 20 minutes—after that chaffing can occur which will make the intercourse uncomfortable to painful.

The anus has no natural lubrication so for guys (and gals too) it’s all about lubrication, lubrication, lubrication. Good tip: Always have a bottle of water based lube at the side of your bed—apply generously and often.

So for the average couple, 15 to 20 minutes of intercourse will probably do the trick. Want the sex to last longer? Well then focus on tons of foreplay and taking a break during intercourse to do other erotic activities.

Regardless, it’s always best to talk about what each other wants and likes. The best part? Just talking about it will get you all revved up and horny.

Should you have sex during your period?
There isn’t any reason why a couple shouldn’t have sex during her period as all aspects of her sexual response are the same. Couples can use a vibrator or have oral sex, if they choose.

What usually stops a couple from having sex during her period is the “ick” factor. If you feel a bit uncomfortable about the potential mess but at the same time are horny, a good idea is to have sex in the shower. Otherwise, a towel under your butt will nicely do the trick.

Some women find the experience quite erotic as she already has the “full” feeling in her pelvic area. Best way to navigate is let her be the guide as to what is going to happen over that five to seven days.

One word of caution: although it is very rare, there is a slim chance a gal can get pregnant. So put a condom on your cowboy if babies aren’t something you want in your immediate future.

There are varying opinions on the “spit-swallow” BJ debate. Is there any reason that one is “better” than the other?
To spit or swallow—that is the question. Some people find it unbelievably sexy to swallow their partner’s spunk, while others are repulsed by the idea. Neither is right or wrong. It really comes down to personal preference.

Men, in general, prefer to have their partner swallow because it keeps the momentum, intimacy and flow of a good blow job going.

If you’re on the fence not knowing if you want to swallow, know your facts. A man will ejaculate between one to three teaspoons of semen—although men want to believe it’s a lot more. The taste of semen is unique to each guy and so if you’ve tried swallowing with one guy and his taste turned you off, it might be a completely different experience with a new fellow. And for those calorie counters, there’s only about five calories per teaspoon—which you’ll be working off during sex so no need to worry.

If you’ve tried to swallow and really don’t like it, no worries. You should never feel guilt about not swallowing when you aren’t comfortable with it. Simply tell your partner, it’s better to have someone giving your Johnson a good licking and not swallow than to have no blow job at all.

And remember, oral sex on him and her can transmit STDs. Always protect yourself when your with a new partner and you don’t know their sexual history.