"My free pass is – because her and Susan are such good friends – is Paltrow," the 51-year-old star said on The Howard Stern Show Thursday. "I gotta get her back in these movies so I can make out with her onscreen again."
Paltrow, 43, played love interest Pepper Potts in the first three Iron Man movies, and although she does not appear in Captain America: Civil War, which has Downey reprising his Tony Stark role once again, he said that doesn't mean she's gone from the Marvel Cinematic Universe.
"She's coming back," he said. "We need her."
Stern asked if that would make his wife jealous, and Downey Jr. responded, "She could care less."
That's probably because this "free pass" only applies if Downey Jr. and Paltrow are "rolling on a take." Plus, he isn't really looking to cash in on his wife's offer.
"I'm very happily married," he said, after explaining that he doesn't go on Facebook and look up exes.
The Iron Man costars reunited in August in a beach selfie that Paltrow, who is currently dating producer Brad Falchuk, posted to her Instagram.
"@robertdowneyjr how I love thee #pepperony," the Goop boss wrote in the caption.