Yes. Nick Cannon and Eminem have been rivals for years now. Though they are both rappers, actors, and entertainers, other than that, they have little in common. The root of their rivalry is their relationships with legendary singer Mariah Carey. Eminem and Carey had a brief romance. A few years later, Cannon and Carey married.
In a diss record, Eminem referenced their rumored romance and included voicemails left by Carey, professing her love for him. Nick Cannon didn't even have a chance to respond, because Carey did the work with her hit single Obsessed. Years later and Cannon and Eminem still go back and forth on diss records, making them more personal every time.
Coming to the conclusion that both Nick Cannon and Eminem are rivals isn't far from the truth. Both Nick and Eminem are not in good terms, and the feud between them has escalated to the point that both rappers have used different kinds of negative words on themselves via social media and even in songs. A perfect example is a song released by Nick Cannon to diss Eminem. The current fight between them was reignited when Eminem jokingly said in one of his tracks that Mariah Carey, Nick's ex-wife, neutered him when they were still married.
This, however, added to the rumors that Eminem and Mariah Carey dated even when she was married to Nick Cannon. This rumor could be attributed to being one of the reasons why both Nick Cannon and Mariah Carey broke up with themselves. However, Cannon also hit back at Eminem, describing him as an old man. Nick Cannon also wants a kind of rap contest between him and Eminem.
The correct answer to this question is yes. Nick cannon and Eminem have been rivals for years. Their feud stems from them a diss record that Eminem recorded, where he insinuated that he and Mariah Carey had a sexual relationship. He also included alleged voicemails from Carey, where she is seen as begging for him and admitting to their romance.
Carey responded with her chart-topping hit "Obsessed." Nick Cannon comes into play because he was Mariah Carey's husband, and Eminem dragged him into the diss. Over ten years later, the two rappers are still feuding, as Cannon continues to defend Carey's honor.