A thing to yell during Sex to test if he/she is paying attention to you when you talk dirty. It can also be used make the other partner uncomfortable, laugh, or possibly questionwhat the hell you are saying.
Running a tug boat means to have 3 men no more and no less than that, tugging one out (masturbating) in a horizontal line side by side all facing one chick and blowing your load all over her.
"Man that chick is so hot."
"Yeah she looks like she needs a good tug boat ran on her."
"Well boys hope you are ready to tug one out, let's fuck up that pretty face of hers."