Wash grapefruit and lemons.
Juice 2 grapefruits and remove seeds. Cut 1 grapefruit into rounds to use for garnish.
Juice Meyer lemons into a separate cup. Remove seeds.
Pour Tequila, Triple Sec, lemon juice, grapefruit juice, and Ice into a cocktail shaker.
Shake for 15 sec.
Before pouring, garnish the rim of your glass. Pour any excess citrus juice into a plate and on another plate place salt and Tajin seasoning. Dip the edge on the liquid first and then, on the salt and chili mixture.
Enjoy!