"She was really upset, and I said, 'Mary, it's, it's going to be OK. You know, don't worry,'" Bush said. "And she said, 'No. Why were you laughing at the things that he was saying on that bus? Why were you playing along with it, Dad? It wasn't funny.'
"I said, 'Mary, I am sorry. And there is no good answer for that.'"
The conversation reportedly took place while Trump and Bush were arriving on the set of "Days of Our Lives" in 2005 for an "Access Hollywood" segment about the businessman's cameo on the soap opera.
Trump is also heard talking to Bush, then the host of "Access Hollywood," about how he tried to have an affair with a married woman and describing how he makes moves on women.
Bush can be heard laughing and later encouraging Trump to hug actress Arianne Zucker, at the time a "Days of Our Lives" star, whose appearance was discussed by Trump and Bush.
Trump dismissed the comments at the time as "locker room banter."
"I apologize if anyone was offended," he said in a statement.
Tune in to "Good Morning America" Wednesday, May 24, from 7 a.m. to 9 a.m. ET to watch Robin Roberts' full interview with Billy Bush.
ABC News' Morgan Winsor, Tom Liddy and Meghan Keneally contributed to this report.