The most obvious reason to host a co-ed baby shower is that you are celebrating more than one new parent. Men are increasingly responsible for parenting, and are often just as interested in honoring their transition into parenthood.
But if tradition or impropriety makes you nervous about co-ed invitations, here are six more reasons to expand your guest list.
Mom-to-be won't be pointlessly terrified
A co-ed shower helps guard against the worst feature of the traditional baby shower: other women's birth stories, told in excruciating detail to a captive guest-of-honor.
These horror stories are all anecdotal evidence devoid of scientific standards of evidence, but they are nonetheless impossible to ignore, and so inevitably wind up needlessly terrifying the mom-to-be at exactly the time she's supposed to be feeling pampered.
There's more time for cocktails
The co-ed shower changes the conversation in part because participants are less comfortable sharing obstetric dramas in mixed company, but also because there's tacit permission to hold a more casual evening event. Kids can be dispatched to a playroom. Spouses can enjoy an evening together. Everyone can eat, drink, and relax.
Changing the feel of the event from quiet brunch to buzzy cocktail party may give you license to revise a few more traditions. For example...
No one will have to eat chocolate from a diaper
Imagine you have never attended a baby shower and at your first one you have to chug from a baby bottle and refrain from saying the word "baby." Inviting men to showers is for the good of us all, because it forces us to re-evaluate the more questionable parts of our celebrations. No one needs to yell "my water broke!" when trying to enjoy a Negroni.
If you and your co-celebrants like games, a co-ed shower offers opportunities more satisfying than the chocolate-filled dirty diaper game. Pile a bunch of diapers (opt for size 2, as some babies skip right over the newborn size) on a table. Fill a wipes container with Sharpies. Ask attendees to write encouraging, heartfelt, or funny notes on the front or back of the diapers. Box up the newly-inked diapers to lighten the parents' first hundred-or-so changes.
The food will taste better
Without the typical shower games, no one will have to eat jarred baby food, so the menu's already looking better. A larger guest list may also encourage you to spend less time making on-theme foods and more time building a grown-up, crowd-pleasing menu. Be the host who orders the duck fat fries.
You can skip the gift opening
One aspect of the traditional shower long lost to history is showering the mom-to-be with gifts that she had not already asked for. There's a lovely sentiment there in the wisdom of parents who have "been there" sharing their must-haves with an expecting mom.
In an age where expecting parents receive gift registry notifications, do we really need to spend three hours with parents opening boxes and saying "Thanks for buying me that thing I asked you to buy me?" That's especially not going to encourage men to start attending baby showers.
If your guests will be shopping exclusively from an expansive registry, consider adding a note to the invitation that gifts should be sent to the parents-to-be, and that what they should bring to the party are their stories. What was it like being a parent in previous decades? What are their funniest, grossest, and heartwarming memories of being a parent to young kids? While your guests are gathered eating and drinking, ask them to share their stories.
You can skip the registry altogether
Hosting a co-ed shower might help your guests of honor skip the registry entirely. A team of spouses is more likely to realize a diaper pail is just an expensive garbage can, that any bag can be a diaper bag if you put diapers in it, and that a play mat is just a really expensive blanket if only one team member has read "must have" registry lists online.
You might also encourage your guests of honor not to register at all: receiving gifts they didn't specifically ask for is a way to learn new things from the well-wishers bringing thoughtfully-chosen gifts, as well as an important early lesson in teaching parents that they do not have total control over the universe.
If you want to see two parents-to-be weep with joy, you can encourage guests to skip baby clothes and gear and shower them with contributions to their child's college fund instead. A lower-budget but equally delightful option is to shower the parents with children's books for their little one's library.