But thankfully the dancing diva, 44, and her choreographer boyfriend Beau "Casper" Smart are able to turn their rehearsals into quality couple time.
"Rehearsal is date night," Smart, 24, told PEOPLE before Lopez's tribute to the late queen of salsa Celia Cruz at Sunday's American Music Awards."We're in rehearsal until 3 a.m. every morning."
In addition to their tireless preparation for the performance, Lopez has also been working on her latest film The Boy Next Door, with Kristin Chenoweth and John Corbett.
"She's filming a movie, so she would come to rehearsal after," Smart says. "So I'd be there like 12 hours and she would shoot like 12 hours [on] the movie and then come to us."
Despite the grueling hours, Smart says they still enjoy it.
"Rehearsal is so fun," he says. "Learning a special move she does in the show was fun."