Sex Ed, Sex Tips

Genital Fit: The Conversation We Should Be Having About Genital Size

January 17, 2022 by Justin Lehmiller

There’s an episode of Curb Your Enthusiasm in which an argument takes place over whether a woman has a “big vagina” or her ex-partner has a “small penis.” While this scene is fictional, it mirrors a lot of real-life talk about genital size: when sex between two people doesn’t feel great, it sometimes gets chalked up to one partner’s sizing “problem.” However, this isn’t a very helpful way of approaching (or resolving) this issue.

We’d do well to switch the conversation away from faulting someone for their size and, instead, talk about the concept of genital fit. I define genital fit as the way in which a given set of bodies and genitals “line up” for a given sex act. There are several degrees of genital fit: it can be painful (when the fit is too tight), pleasurable (when the fit is just right), or there can be a lack of sensation (when the body parts just don’t line up all that well).

Genital fit can play a role in any partnered sex act (including oral, vaginal, anal sex), no matter the partners’ sex/gender, orientation, body size/shape, or ability status. It’s also something that can change over the course of a relationship. For example, oral fit can change if you experience a jaw injury or TMJ, vaginal fit can potentially change following childbirth, and penile fit can change if your erections start becoming less full.

Genital fit encompasses a lot of different things, including penis length and girth (as well as its overall shape and proportions), vaginal depth and width, anal diameter, pelvic floor tightness, as well as the size and shape of the mouth. However, it’s also affected by each partner’s overall body shape and size, ability status, and health. All of these things can affect angles of penetration, as well as what positions and activities are comfortable and feasible.

What all of this means is that some sex acts are just going to be easier and more physically pleasurable for some partners because their bodies and genitals simply “line up” in a way that provides optimal stimulation. For those who don’t have an easy fit, however, sex may feel uncomfortable or unenjoyable.

Genital fit isn’t something you can really predict in advance of sex because there are a lot of variables that play a role in it. And sometimes the partners who are most attracted to one another aren’t necessarily the best fit in this regard. It’s also possible to be highly aroused by physical traits that don’t translate to good genital fit. For example, you might find the idea or visual of a particularly large penis to be arousing, yet find that accommodating it in your body is painful or uncomfortable (as I’ve said before on several podcasts, “sometimes the eyes are bigger than the hole”).

So if you’re with a partner with whom you don’t have great genital fit, what can you do? There are a lot of options, but ultimately it’s about being adaptable and creative in finding a solution.

For example, I’ve heard from several readers who struggle to enjoy performing oral sex on a larger than average penis because they find it to be physically uncomfortable. Given that you can’t really increase the size of your mouth or decrease the size of your partner’s penis, you need to get creative. This might involve not trying to deep throat , using your hands or a sex toy (such as an open-ended stroker) to assist, using your tongue to perform more of the stimulation, incorporating a lubricant, or trying a new position.

If vaginal tightness is a concern, the solution might be not rushing into penetration and starting with relaxation exercises and dilators (which can also help with anal tightness). It might also involve easing up on the Kegel exercises if your pelvic floor is particularly tight, or maybe looking into Botox injections. By contrast, if vaginal looseness is a concern, then it might be working on your Kegels.

If the concern is smaller penile length or girth, the solution might be looking into toys such as sleeves or girth enhancers, trying different positions that allow for deeper or fuller penetration, or maximizing size with penis pumps or rings (or if your erections aren’t as full as they used to be, talking to your doctor about ED medications).

Yet another possibility is to simply expand your definition of sex—sex is more than just intercourse. Try new and different activities together and expand the options on the menu. Sex can be whatever you want it to be!

You can also combine multiple solutions to try and find the best fit.


The partners we want to be with aren’t always the partners with whom we have the best genital fit, and sometimes a good genital fit decreases over time in a relationship. This is an issue that can often be resolved with a flexible, adaptable, and creative mindset for sex. However, not everyone will find a mutually acceptable solution, especially if they’re dealing with a particularly large fit discrepancy—in which case they need to decide how important genital fit is in the relationship.

Above all, remember that when genital fit is an issue, it’s not helpful to blame or shame a partner for their body parts. It’s also not just one partner’s job to find a solution. Sexual problems are best addressed when everyone is invested in working through them together.

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Image Source: Photo by Deon Black on Unsplash

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Written by
Dr. Justin Lehmiller
Founder & Owner of Sex and Psychology

Dr. Justin Lehmiller is a social psychologist and Research Fellow at The Kinsey Institute. He runs the Sex and Psychology blog and podcast and is author of the popular book Tell Me What You Want. Dr. Lehmiller is an award-winning educator, and a prolific researcher who has published more than 50 academic works.

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