Little boy

While friga is showing Loki around earth
They stumble on a young boy
His name is Perseus Jackson and without odins permission she takes him home

She hides him from Odin

Wen Loki is feeling neglected he goes to his favorite brother
Percy Jackson

When percy is sent off to camp Loki grows up mad and sad

And so when the war with the chitari starts percy gets involved with the avengers