I thought that this was maybe a joke put on by the guys around me, until I asked guys, "What do you think when you see this shirt?" Most of them answer the same thing as above. So point proven.
Maybe this is why guys enjoy engineering...everything is about symmetry. But in their minds, they think about the following Free Body Diagram:
But how does the shirt stay up? This is why guys are so hesitant about the situation...What holds the shirt up?! But our Free Body Diagram isn't complete...
YAY! We didn't break Statics!
The pressure from the elastic helps to allow the moments on the shirt. Now the free body diagram is complete.
And that is engineering for you. Maybe the gals do have it figured out :-P
*Image courtesy of karenmillensaling.com and Serena's wonderful drawing skills via Microsoft Powerpoint.