In the DC Universe, no one denies that Nightwing is an extraordinary fighter and acrobat, but his costume also has another deceptive feature that helps him in battle: it makes him look sexy.
Although they have similar histories as orphans, as individuals, Dick Grayson and Bruce Wayne couldn't be more different. And this difference in character is also reflected in their fighting styles. Bruce is a brawler. He gets down and dirty with his opponents, slugging it out when necessary. In contrast, Nightwing is an acrobat. He uses high-flying agility to outmaneuver his opponents. These different styles are also reflected in their costumes. Batman has more of a bulky armor and cape to inflict fear whereas Nightwing wears a skin tight suit that allows maneuverability and minimum friction as he spins through the air.
But there is an added benefit to Nightwing’s sleek and simple suit rather than just being physically practical in combat. In 2004's Nightwing # 95, which was written by Devin Grayson and illustrated by Mike Lilly, Nightwing fights alongside Tarantula to take down Copperhead. The villain is too much for Tarantula to handle, so she mainly watches as Nightwing fights. She also its to having a little crush on Nightwing and has something to say about the ex-Robin's costume. She says it’s a little small and he can wear something a couple sizes up. But she also says that she (nor anyone else) is complaining, hinting that Nightwing's sexuality might come in handy during a fight.
This is a very interesting choice to the super hero gender dynamic of costumes. It is the women who are usually known for having revealing attire that show them off in a sexual manner. Specifically, Power Girl's notorious "boob window" comes to mind. Superhero comics are riddled with male villains making comments about female superheroes' attire before getting their butts kicked. This is a bit of a role reversal as Nightwing showcases his assets in a unique way.
It's also fitting that Nightwing is the hero to do this as his butt has reached a certain legendary status in the comics community. It's become a running joke of sorts that Nightwing's butt is something to behold, with fans even making memes about Will Smith smacking it. So while his skintight costume certainly has practical uses for helping with his fighting style, the outfit also has other benefits of showing off just how many squats Nightwing has been doing on his off days.
