Sean ‘Diddy’ Combs is set for a TV showdown with his ex-girlfriend Jennifer Lopez after signing up to perform on American Idol.

The rapper will perform his latest single Coming Home, mentor the show’s contestants and dress them in his Sean John designs on an episode due to air next month (Apr11).

And he insists he can’t wait to spend some quality time with his former lover, who is wowing critics as a judge on the hit talent contest.

He says, “She’s just looking so good. You’ve got to give it to her for having twins and to be doing it how she’s doing it. I’m so proud of her.”

Combs is also a big fan of her judging skills, telling news show Access Hollywood, “The way she handled coming after (former Idol judge) Simon (Cowell)… she’s been, like, a compassionate person. She has made me cry, like, twice, and she’s looked good doing it. And she has made sense.

“She’s a nice person (and)… when you’re super nice, your emotions get the best of you. It’s good though, it’s good to see that change in the competitive shows. I think she’s very refreshing.”

Lopez broke down in tears on the show last week when she had to send a favourite contestant, Chris Medina, home.