The Still Water star, 50, appeared on SiriusXM's The Jess Cagle Show on Tuesday where he was asked about his longtime friend and collaborator, Affleck, 48, and the actor's reignited romance with Lopez, 52.
"You're very happy for Ben Affleck and Jennifer Lopez," co-host Jess Cagle teased the actor. "I know you love getting asked about that."
Damon replied, "Right. But how else would I be? Like, would I be unhappy? Like, 'I hate true love.' "
The actor continued, joking, "It sucks. Yeah. Yeah. I wish them nothing, but you know, hardship."
Theo Wargo/Getty Images; Rodin Eckenroth/FilmMagic; Emma McIntyre/Getty Images
Earlier this week, Damon appeared on Extra promoting his film where he said he was "just so happy" for Affleck.
"He's the best. He deserves every happiness in the world," Damon said of Affleck's relationship with Lopez. "I'm glad for both of them."
The couple originally began dating in July 2002 after filming Gigli together. They got engaged that November before postponing their September 2003 wedding, just days before the date, and ultimately calling off their engagement in January 2004.
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Last weekend, the duo celebrated Lopez's 52nd birthday while on a yacht tour of the Mediterranean.
On Tuesday, a source told PEOPLE the couple was "very much enjoying their vacation."
"This is not a summer fling. They are planning a future together," said the source. "They have serious talks about how they can make it all work. Between their relationship, their kids and jobs, they know it will be tricky to balance it all."
The source added, "Jennifer is the happiest. She keeps gushing about how amazing Ben is."