It's not like he's O.J. Simpson ... but Justin Bieber took the law and a Dos Equis into his own hands Friday night in Houston.
Biebs was partying at Nox Houston before grabbing a piece of ass at a local strip club ... which could explain why JB was so handsy around the nudie dancers.
FYI -- It's illegal to drink in Texas if you're not 21.
The bar management claim they never served him alcohol ... but as far as we know Speedy Gonzalez wasn't racing around the bar handing out Dos Equis.