To talk shit. Usually without warning (as with a laxative, except for your mouth).
Dumbass: "Yo fuck you, I ain't scared of you, or your boys or nobody, you're a little bitch and I fucked your girl!"
You: "Whoa buddy, I just whupped your father's ass with both hands behind my back and your mom's giving me sexy eyes. Why you laxatalkin'?"