Roslyn Corrigan told Time magazine that she was 16 when Bush grabbed her buttocks as she posed for a photo with him in 2003 at a gathering of CIA officers north of Houston. She attended the event with her mother and father, who was an intelligence analyst.
"My initial action was absolute horror. I was really, really confused," she told the magazine. "The first thing I did was look at my mom and, while he was still standing there, I didn't say anything. What does a teenager say to the ex-president of the United States? Like, 'Hey dude, you shouldn't have touched me like that?'"
A spokesman for the 41st president, Jim McGrath, said in a statement Monday that Bush regrets any offensive actions.
"George Bush simply does not have it in his heart to knowingly cause anyone distress, and he again apologizes to anyone he offended during a photo op," he said.
Time spoke with seven people who said they had been told by Corrigan about the encounter in the years afterward.
Corrigan is at least the fifth woman to say Bush groped her. Time reports that a sixth woman, a retired journalist in Pennsylvania, posted to Facebook last month that Bush touched her from behind during a 2004 photo opportunity.
The stories came to light after television actress Heather Lind said last month that Bush, now 93, touched her from behind and told a dirty joke while they were posing for a 2014 photo. McGrath at the time explained that Bush has been in a wheelchair for about five years "so his arm falls on the lower waist of people with whom he takes pictures." Bush, who served as president from 1989 to 1993, has vascular parkinsonism, a rare syndrome that mimics Parkinson's disease, and he uses a wheelchair for mobility.
"To try to put people at ease, the president routinely tells the same joke and on occasion, he has patted women's rears in what he intended to be a good-natured manner," McGrath said.
Bush was standing alongside Corrigan for the photo taken in 2003. McGrath's statement Monday did not elaborate.