Huh? Neither of us are "tethered" to you. I asked you to come because I worry about you and want to make sure you're okay.

[ It's less tether and more... him wanting to handcuff himself to Dazai so he doesn't go running off onto the train tracks or something. He already had to see Dazai die once; he doesn't want there to be a second time Dazai dies, because he was neglected. Even if Dazai says he wants to live- even if he earnestly means it- it's scary and hard to shake that worry. ]