"Watching Nick rest his head on your shoulder may be one of the most beautiful sights that I have ever seen,'' Hoda said on the fourth hour Thursday.
Al then opened up about his relationship with Nick, 17, which includes everything from cheering him on at a race in New York City to getting a manicure and pedicure together to prepare for 2020 in style.
Al described Nick as "somewhere on the autism spectrum" in an essay for Guideposts magazine last year.
"The thing I love about him, that I admire about him, is that he just kind of attacks it head-on,'' Al said Thursday. "He's very goal-oriented, and he's a great kid."
Al, who spent New Year's Day hosting the Rose Parade in California with Hoda, said that one of his goals for the new year is to be more patient, particularly at the end of a long week, when he says he can "tend to be a little short with Nick."
"As a lot of parents (know) who have kids with special needs, they can try your patience,'' he said. "Not that they mean to or anything like that."
Nick serves as a constant inspiration for his father.
"I look at him and all that he does, and I want to be a better person for him,'' Al said.
In addition to their regular mani-pedis, they also have a yearly tradition of finding their perfect Christmas tree.
"Joel and I often talk about you and your son because he's an incredible kid,'' Hoda said. "We've watched him grow over the years. He has an issue that he deals with, and you guys have figured (it) out."
Hoda marveled at the patience Al shows when he's with Nick.
"You saw me on a good day!" Al joked.