When he opened the anonymous video, he didn't expect to see his partner being tortured by the Joker.

"You fucking monster...!" He clenches his jaw in anger, he had so much will to spend to not punch the monitor in front of him.

You scream painfully in that video which only makes his blood boil more. Joker definitely knew Jason's relationship with you, he's your husband and his idiotic self didn't keep it secret perfectly. Jason should've listened to you when you told him to drop this vigilante job.

Now he's paying the price for being stubborn, he either has to give Joker the information he wants, or watch you die.