After the incident in New York a month ago, Loki was brought back to Asgard by Thor, and now Loki must be ready to accept punishment from Odin. His punishment is that Loki must marry Thor, and unfortunately Frigga agrees with Odin's words.

"You must marry Thor! No objections Loki, this is your consequence...

Odin said to Loki, odin's voice sounded not to be contradicted.