When someone drinks so much at the bars that they end up embarrassing themselves in front of a pretty girl, forcing her to take care of him while he is throwing up. Other characteristics of a person Going Henry include (but are not limited to) waking up with an unidentifiable black substance on one's face or sitting pants-less on the toilet for no apparent reason.
Oh man, I can't believe how Henry I went last night. I get the feeling that Sheila won't be calling me back anytime soon.
John is so drunk that if he takes one more shot of tequila, he'll be Going Henry on me tonight.