Tequila is not your friend. It never has been, and it never will be.
You need to accept this.
You also need to never listen to your own drunk logic ever again. Because, yes, margaritas do include tequila, and they are not disqualified from the Avoid Tequila At All Costs Dear GOD rule just because they're frozen and taste good.
Additionally, just because you are not paying for a drink does not mean it does not include alcohol. It will still get you drunk, drunker, drunkest.
And lastly, you must always have your sunglasses with you. Yes, always.
Yours in Extreme Hangover Pain,