Following a fiery Twitter exchange between the two on Thursday, Romero personally called into Bisping's SiriusXM show The Countdown to confront Bisping live over the phone line.
The phrase "poopy-pants" may or may not have been repeated several times.
Audio of the exchange can be heard below.
Afterward, Bisping continued the feud online, tweeting several toilet emojis at Romero.
The back-and-forth took place just one day after Romero trolled Bisping by setting up a GoFundMe account to help pay for Bisping's medical expenses and retirement party after the two potentially compete later this year.
Romero is currently the assumed No. 1 contender for the UFC middleweight belt. Following successful knee surgery, Bisping is expected to return to the cage to defend his strap later this summer, possibly in May.