Kermit the Frog is moving on. After 40 years with Miss Piggy, he's got a new, svelter, blander, girlfriend named Denise—who is, somewhat improbably, also a pig. Reaction to the news has been mixed. Jezebel accused Denise of being a homewrecking hog, while The Guardian's Megan Carpentier noted that Miss Piggy was always more interesting and accomplished than Kermit anyway. "Nowadays, Miss Piggy is a beloved feminist icon," Carpentier declares, and “Kermit’s the behind-the-scenes wet noodle still whining about how hard it is to be green while picking up goodness knows how many of Hollywood’s near-infinite star-chasers."

This is all in good fun, of course. But it's interesting that much of the light-hearted gender analysis has focused on Kermit as a faithless two-timing patriarchal jerk. There's been relatively little discussion of the most salient aspect of the now-terminated relationship: Piggy regularly beat up Kermit. Hiiii-ya.

Again, this is a Muppet pig and a Muppet frog we're talking about. But still, the fact that the Piggy/Kermit relationship could be seen as harmless fun had a lot to do with the fact that the violence in their relationship was female on male rather than the other way around. If Kermit were constantly hitting Piggy hard enough to knock her off her feet and into nearby furniture or shrubbery, there would be cultural pushback. People are well aware that in real life, without puppets, men regularly beat and harm their significant others; the National Coalition Against Domestic Violence says one in three women experience physical intimate partner violence during their lives. As a result, representations of men beating their wives — even if it's a frog beating a pig — don't generally strike people as funny.

Girlfriends beating their boyfriends, on the other hand, is considered safely rare. But how rare? It’s an extraordinarily controversial question. Many feminists and researchers are reluctant to discuss or give theoretical weight to incidents of violence by women against men, as Jennifer Gaboury wrote at Feministwire. Some activists fear that acknowledging violence against men will stigmatize or criminalize women who attempt to defend themselves. Others worry that "it could mean a loss of scarce resources for women who do not, overall, have the same earning capacities of men."

A substantial body of research indicates that domestic violence against men is not rare. The NCADV, for example, say one in four males suffer physical domestic abuse. It may even be more common than that. "My reading of the available evidence, which has been piling up for decades now," Adam Jones, a political scientist at the University of British Columbia who works on gendered violence issues, told me by email, "is that women in the US and Canada are just as likely to aggress against their intimate partners, verbally and physically, as men are. That goes for both straight and gay."