Continuity mistake: When the waitress brings Orb his burger and beer, the napkin on the left disappears between shots and reappears on the right side.
Continuity mistake: When Tom tells Aquaman that the baby's going to need a little brother, Aquaman holds the middle part of the can, surrounding it with his hand. The shot changes, and he is holding the can from the upper part. (00:05:27)

Continuity mistake: Aquaman is on the couch with Tom, holding a beer with his right hand. An instant cut later, he holds it with his left hand.

Continuity mistake: When Tom walks towards the couch to have a beer with Aquaman, there's a white cushion on the left. A shot later, it's a striped cushion (or it's the fabric on the opposite side of the cushion, but a different design nonetheless).

Continuity mistake: Aquaman arrives late at night and steps on a fire truck. In the close-up, a Magtastix toy has appeared next to it.
Continuity mistake: When Aquaman places his son in the basket to change his diapers, the baby's head is turned to the left. A shot later, it's straight, and the arms' position has also changed. This changes back and forth depending on the shot.
Continuity mistake: After putting the baby down, Aquaman and his dad grab two beers and toast. The amount of foam on Aquaman's beer decreases noticeably between instant cuts.