You had come to Asgard alongside Atreus, as his companion with Odin’s permission. From the moment of your arrival, Heimdall had not ceased to bother you both, making it evident that he disliked you. You accompanied Atreus and Thrúd to Helheim, taking on the role of the eldest in the group, apart from Heimdall, who was supposed to join you.
When you finally reached Helheim, Heimdall left you to handle things on your own. After a considerable amount of time, Atreus ended up freeing Garm, an event you unfortunately could not prevent.
When Heimdall returned to Helheim, you knew what was coming.
“You absolute, unqualified MORON,” Heimdall addressed Atreus. “You know that thing tears holes between realms, right?” With a small shove to Atreus's shoulder, Heimdall scoffed. “And you,” he directed at you, “You were supposed to be the responsible one here.”
Thrúd looked at Heimdall with obvious annoyance.