A new study says men don't "grow up" until age 43 -- a full 11 years after women do.
And both men and women agree that's the case, according to the research commissioned by Nickelodeon UK to mark the launch of its new show "Wendell & Vinnie."
Study participants of both sexes said they believe women reach maturity much earlier than men -- age 32 to be exact.
Women were also twice as likely to feel like they were the "grown up" in their current relationship, and a quarter of women surveyed claimed they made all the important decisions in the relationship, The Daily Record reported.
Thirty percent of women said they had ended a relationship over their male partner's immaturity.
And a whopping 46 percent of women reported relationships in which they had to mother their male partner a bit too much, The Telegraph reported.
But immaturity isn't all bad.
Four in 10 people surveyed said it can keep things fresh and ensure the relationship stays fun.
TOP 30 MALE MATURITY FAILINGS (according to women in the study):
1.Finding their own farts and burps hilarious
2.Eating fast food at 2 a.m.
3.Playing video games
4.Driving too fast or 'racing' another car at the lights or on the highway
5.Laughing a bit at rude words
6.Driving with loud music
7.Playing practical jokes
8.Trying to beat children at games and sport
9.Staying silent during an argument
10.Not being able to cook simple meals
11.Re-telling the same silly jokes and stories when with the boys
12.Don't like talking about themselves/ having proper conversations
13.Hating books/reading because of short attention span/they're boring
14.Doing crazy dance moves
15.Mom still doing their washing
16.Having their mom still make them breakfast/any meal