Of course not.
However, I have found a video that does point out a few coincidental similarities between the two songs.
As the clip shows (via Vulture), one of “OMG” ‘s hooks (and one of the song’s more ridiculous lyrics) does sound a lot like Homer Simpson’s 2003 holiday ode “Christmas in December.” Again, it’s unlikely that Usher sought songwriting assistance from a yellow, four-fingered cartoon icon, but it is awesome to hear Usher and Homer duet.
If this incident does somehow become a plagiarism case, “Simpsons” lawyers will likely provide evidence that the song’s writer and featured guest, Will.i.am, has been accused of lifting melodies and samples (most recently, by George Clinton) numerous times over his Black Eyed Peas career. We don’t think Usher would intentionally steal from “The Simpsons,” but Will.i.am has traveled to a sort of cartoon dimension in the past.