When a girl gives a blow job/hand job combo while inserting a finger in the guy's ass.

It's a very rare maneuver not recommended for new couples.
Guy 1: This girl was blowing me last night and she stuck her finger up my ass!!

Guy 2: Dude! That's a Mexican Tugboat!!
by MikeandJohn January 30, 2011
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The act of fisting a man's ass so deep that you are able to reach into his penis and wear his penis as a finger glove, moving it to-and-fro as you will. The act is then completed by pulling the penis inside out back through his body so that his penile skin concaves inward from the outside. This concave is then filled in with the lubricant of choice (generally microwaved mayonnaise) and is then fucked by the person performing the act until the lubricant (again, generally mayonnaise) has been pulverized into a gelatinous solid. This gelatinous solid is then placed atop street tacos and called "cotija cheese" and eaten by both parties.
Man #1: Dude, my cock ain't been the same since I got that Mexican Tugboat last week. Straight up lookin' like a windsock up in this bitch, still smells like dried mayo and cheese, too.

Man #2: I know what you mean, after 5 or 6 Mexican Tugboats, your cock is pretty much just a worn out garden hose full of rancid dairy products. Sure feels great though!
by Popadopolis_FTS October 31, 2014
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