Apparently Affleck really digs fans who cosplay as Harley!
Affleck'sBatman v Superman co-star, Cavill, looked just as handsome at the event. The 33-year-old actor sported a navy blue checkered suit, which he paired with a gold tie and dark brown dress shoes.
Momoa -- who played Aquaman in Batman v Superman and will also star as the superhero in 2017's Justice League and 2018's Aquaman– opted for a more casual look: a black T-shirt and dark gray pants, styled with shoes oddly similar to Cavill's, plus a bronze chain hanging from his belt.
The 37-year-old actor actually looks like he could be vying for the part of Thor with those long blonde locks -- but that would be the wrong comic universe.
The Justice Leaguers let the Suicide Squad cast take center stage, however, standing on either end of the group photo.
The appearance comes on the heels of the trio's showing in San Diego, California, last month, where they assembled for their first Justice League group gathering along with Gal Gadot, Ezra Miller, and Ray Fisher. That event is also where Affleck confirmed that he will be directing the solo Batman flick.
But don't worry -- the guys didn't take all the thunder away from the Suicide Squad cast, who made nearly as spectacular a splash in London as they did at the film's New York premiere on Monday.
Jared Leto played up his role as the Joker in a long bright green coat, pastel pink pants, and the same smoking slippers he rocked with his lion coat in NYC.
Margot Robbie, who stars as Harley Quinn, took a cue from Leto's look earlier this week. She stunned in a white maxi dress that featured a roaring lion on her bust and embroidered flowers along the straps, waist and hemline.
Not to be outdone, Cara Delevingne channeled her character, Enchantress, once again. The British model-actress' goth queen ensemble was comprised of a leather jacket with half velvet, half sheer sleeves and a slew of pins, plus a completely sheer lace dress styled with matching black high-waisted underwear, thigh-high heeled Christian Louboutin boots, and two bracelet cuffs.
It's been a busy week for not just the DC family but Affleck's brood as well. His estranged wife, Jennifer Garner, made her own fetching appearance on Monday at the premiere of her new film, Nine Lives, turning heads in a bold red fit-and-flare Alaia dress.
On the red carpet in Los Angeles, Garner spoke to ET about making a movie that her and Affleck's three children -- Violet, 10, Seraphina, 7, and Samuel, 4 -- can go see. Find out more in the video below.