7.When he revealed that he sent Anthony Mackie a pocket square for Christmas.
8.When Sebastian drank wine and started binge-watching Gossip Girl.
9.When he came up with this nickname for his fans, and then he and Anthony couldn't stop laughing about it.
10.When he told the story about how he almost said hi to Paul Rudd when he saw him on the street, but he was on the phone with his therapist.
11.When Sebastian was filming this really intense Bucky moment for Captain America: Civil War, and the door fell off Bucky's cell.
12.When he stopped an interview so he could say hi to Elizabeth Olsen, and then he got flustered when she complimented him too.
13.When he was just cuddling Bucky's prosthetic arm behind the scenes.
14.When Sebastian read a mean tweet about himself and gave this sad face as a response.
15.When he showed off the Falcon cutout he has at his house, because real BFFs keep cardboard cutouts of each other.
16.When Sebastian shared this absolutely flawless birthday post for Anthony on his Instagram story.
17.When he practiced for weeks just to make sure he got Bucky's iconic knife flip down before filming Captain America: The Winter Soldier.
18.When he was hilariously upset about this combination of emojis that represented the Winter Soldier.
19.When it was revealed that Sebastian was voted "most likely to be in the bathroom fixing his hair when he receives his first Oscar" in his high school yearbook.