[Gokudera folds his arms at her mentioning that she ought to punch him. He lifts an eyebrow at her and shakes his head gently.]

We hardly know each other! I've been walking around with this... self-destructing jewelry and not telling anyone because it is a major weakness.

I wouldn't just message someone I barely know out of the blue to say 'hey I need you to hold this collar up so it won't cut off my head!'

[His tone goes a bit imploring and he's looking at her with shame.]

I didn't know I could trust you.

[Gokudera isn't able to keep eye contact with her, even if she is smiling at him. No matter how awkward or kind, he can't shake the fear of death. Of admitting to it's possibility in this matter. That makes it too real.]