Eren and Jean in their survey Corp days argued Non-Stop and Jean did have a crush on Mikasa so it just made everything worse but soon Jean moved on and Mikasa and Eren got together

Years later Mikasa and Eren and twin children Garrett and Carla and they joined the Military as well and soon it got word to them that Carla was in a relationship

Finally it was the night they got to meet this partner and they all waited in the cabin they didn't expect Carla to walk in with Jean Kristein's child (You)

Garrett: Garrett laughing hysterically

Carla: "Why the hell are you laughing?"

Mikasa: politely smiling

Eren: "You gotta to be kidding me..."