Make way in the shower ladies.  The baby shower that is - because the male invasion into this previously all-female affair has begun. 
 
And it's not necessarily a bad thing.  This is the modern baby shower in action. The advent of more males attending baby showers has tended to turn the baby shower gathering into less of a game playing event and more of a social gathering where couples get to share in the excitement of the coming baby while enjoying each others company.
 
Baby shower invitations for the men means the baby shower menu might lean more toward some poolside barbecue action and less indoor finger foods and baby games.  Not many men will be vying to see how fast they can dress and undress a baby doll. Though, on the other hand, that could make for an interesting competition with the women.  
 
Likewise, the more men that are invited the less feminine the baby shower theme.  Maybe less of a Winnie the Pooh baby shower theme and more of a Pittsburg Steelers theme.  You could even get a Terry Bradshaw bobble head doll. Okay, on second thought you don't want to scare the tot when it
arrives.  So, maybe there is a baby shower middle ground there somewhere...
 
If men are invited you might want to mix up the baby shower games as well.  Maybe alternate baby shower bingo with a round of Texas Holdem.