"I'm a little disappointed it hasn't happened yet," former President George W. Bush tells December's AARP The Magazine. "But the more disappointment I show, the less likely it is things are going to happen on the time table I want."
He may be in for a wait since 28-year-old daughters Jenna Bush Hager, who married in 2008, and Barbara Bush are both focused on their careers. Jenna told PEOPLE in May that it will be "years" before she gives her parents grandkids. Fortunately, Bush has his wife Laura to keep him company.
"She's busy and I'm busy which makes our marriage not only interesting but exciting," says Bush, 64. "But we always make time for each other."
While the former chief executive, currently promoting his book Decision Points, voices some regrets about his time in office, he's proud of Laura's role as First Lady and their marriage.
"I meant it when I said she was the greatest First Lady ever. Because she viewed the presidency and the First Lady as an opportunity to improve people's lives," Bush says. "She put her heart and soul into the experience, just like I did. So we had a shared experience. That makes a good marriage better."