WARNING: The following article contains spoilers for Batman: Hush, available now for digital download.
Bruce Wayne is the most famous notoriously single playboy in the DC Universe in comics. In the world of DC Universe Animated Original movies, we haven't seen much of Bruce Wayne's leisure activities, since he's been way too preoccupied with the Justice League and Bat-Family.
However, in Batman: Hush, one relationship resurfaces up to haunt him, his tryst with Talia al Ghul. That union resulted in the birth of Damian Wayne, who became the new Robin. In a reverse version of "the talk," Damian reminds his father of that fact when Bruce decides to pursue a relationship with Selina Kyle in one of the film's strange, but funny moments.
This movie, as per the source material, highlights Bruce's romance with Selina Kyle. After they keep coming back to each other to steal kisses on night-time rooftops, he realizes that as the Batman he can't be with her, so he decides to let Bruce step in, since there's already chemistry between him and Selina. She also opts to leave the Batman/Catwoman affair behind, and they begin dating publicly as she wants a new life for herself and sees Bruce as someone she can love.
As Bruce heads out to meet her with flowers and to admit that he's in love with her, Nightwing and Alfred are relieved to see him happy at last. But Damian isn't so excited, and he calls his father as he's en route to dinner. Damian is upset his dad is going out with a criminal, and as much as Bruce emphasizes she's an ex-criminal, the new Boy Wonder doesn't buy it at all. Damian understands their mission is a lonely endeavor, a curse all vigilantes face, and that love lives aren't a luxury they can afford as they'll endanger their significant other. This leads to him offering up some really odd advice.
Damian takes it a step further by referencing his dad's poor choices in the past, including but not limited to his own mother, Talia. He admits he's grateful for their drunken tryst, but Damian fives his father some odd, very surprising advice when he says," I must insist you use protection. And another thing, cover your drink!"
He doesn't get to go any further because Bruce hangs up, clearly uncomfortable with the chat. It is a clear reference to DC lore and the Son of Batman animated film where Talia drugged Bruce and enjoy a heated night that led to eh conception of Damian.
As humorous as this scene may be, it's also true to Damian's character, since he doesn't want anyone or anything distracting a member of the Bat-Family, especially his father. While it might seem overprotective, Bruce's choices have had legitimately bad consequences in the past.
After his flirtation with Talia, she had Damian, who Ra's then trained to be the Demon's Head in the DCAU. Deathstroke would attack the family to claim the League of Assassins for his own, leading to a war that saw Talia trying to rebuild the society, leaving Damian with his father in what would end up being a permanent spot as Robin.
While it makes sense for Alfred or Dick to drop some advice like this on Bruce, Robin takes the initiative, candidly speaking based on his dad's past experience all in the name of tough love.
Directed by Justin Copeland, Batman: Hush stars Jason O'Mara, Jennifer Morrison, Jerry O'Connell, Rebecca Romijn, Rainn Wilson, Sean Maher, Bruce Thomas, Stuart Allen, James Garrett, Maury Sterling, Geoffrey Arend, Vanessa Williams, Jason Spisak, Adam Gifford, Dachie Alessio, Peyton List and Tara Strong.