McCarthy had poked fun on the micro-blogging site over the rumour that Smart cheated on Lopez with a transgender model, reported Ace Showbiz.
"Did Jennifer Lopez's boyfriend cheat with a transsexual model? I heard JLo gave him an ultimatum: 'it's either me or her/him'," her tweet read.
Some users called McCarthy bigoted and transphobic in response to her tweet. Though, McCarthy did not reply, she removed her tweet.