Sex & Relationships

A Sex Educator Explains What To Do If Your Partner’s Penis Doesn’t Fit

Ah, the ancient problem of the mare and the horse.

by Emma McGowan
Young couple romancing in bedroom at home

In this week's Sex IDK column, Emma McGowan, certified sex educator and writer, answers your questions about a mismatch between penis and vagina size.

Q: Is it normal if my partner's penis doesn't fit all the way inside of me?

Penis size is something that so many people — of all genders — have questions about. Is it too big? Is it too small? Is there such thing as the right size? But this question, Reader, is especially interesting because it’s not the standard penis-size question: It takes your body into account as well. So, let’s dive in.

First off: There’s no such thing as “normal” when we’re talking about sex, genitalia, sexual preferences, or really anything to do with human sexuality. There is such thing as average when it comes to size — and the average penis size is about five to seven inches when erect — but “normal” doesn’t exist. (Even average is a debatable concept because it’s very likely that no one human actually fits the true definition of average. But that’s a topic for another story.)

There’s also an average depth for the vaginal canal, which stretches when a person is turned on, just like a penis grows during arousal. According to sex researchers Master and Johnson, the average depth for an unaroused vagina of someone who has never given birth is 2.8 to 3.1 inches and 3.7 to 4.1 inches when aroused. And according to Planned Parenthood, unaroused vaginas can range from two to four inches and be aroused from four to eight inches.

I know there’s a range there, but those numbers can help us see that, yes, it’s very likely that there are many couples out there who are mismatched in size. For example, if one person has a vagina that is four inches when aroused and their partner has a penis that is seven inches when aroused, only about half of that penis will fit into that vagina. And that’s when both people are both within the “average” size ranges, right? So, if we pushed this thought experiment even further, then there are likely couples where the penis is ten inches, and the vagina is, say, two!

The mismatch between penis and vagina size is even referenced in the Kama Sutra, an ancient Sanskrit on love, sex, and marriage, which specifies animals for different genitalia sizes. For penises, it’s hare (small), bull (medium), and horse (large). And for vaginas, it’s deer (small), mare (medium), and elephant (large). According to the ancient Sanskrit text, a horse and a mare are an “unequal” union — aka not a great idea because that penis isn’t going to fit well in that vagina. Likewise, a hare and an elephant won’t be a great fit either, because the penis will be too small for the vagina.

But if you’re more of a deer and your partner is horse, that doesn’t mean you’re doomed! There are plenty of sex acts that don’t involve a penis going into a vagina. In fact, I’d even go so far as to say that a size mismatch could be a blessing in disguise because it encourages you and your partner to get creative. Why not spend hours going down on each other? Practice your hand job skills? Invest in a great cock ring for penetrative sex? Explore some kinks that don’t involve penis-in-vagina sex? There are a lot of options out there for a hot, interesting, and varied sex life if you’re willing to do some exploration.

You should also consider your menstrual cycle. The cervix (which is the end of your vaginal canal and the beginning of your uterus) changes in both texture and its position in your body, depending on where you are in your cycle. Your cervix will be lower and harder near your period, but near ovulation (which is halfway through your cycle), your cervix will be higher and softer. That means that you might be able to fit more of your partner’s penis inside your body when you’re closer to ovulation than when you’re closer to your period.

Of course, suppose you’re trying not to get pregnant. In that case, you also need to be extra careful about using a condom or another contraceptive method if you’re having sex near ovulation. But this change in depth due to your cycle isn’t relevant if you’re on hormonal birth control, like the Pill, because you're very likely not ovulating.

When it comes to anal sex, the rectum doesn’t change in shape the way the vagina does. But the average size of the rectum ranges from around six to eight inches.T hat means it will more easily fit an average-sized penis than the average-sized vagina will. Does that mean it that every penis will fit in every butt? Nope! But it does mean that it’s more likely to fit.

If you’re experiencing a mismatch with your partner, Reader, and it’s bumming you out or interfering with your sex life, there are some things you can do to make penis-in-vagina sex feel better. First, make sure you're really turned on before your partner enters you. That ensures that your cervix is as far up in your body as possible, making it harder for him to hit it. (Trust me: You don't want him to hit it.) You can ease entry with a high-quality lube, which will help everything slide around nicely. And, finally, I recommend checking out Ohnut. It’s a customizable stack of rings that your partner can wear on their penis in order to control depth of penetration — a very 2020 solution to the ancient problem of the mare and the horse.