my boyfriend wants all my passwords?

He wants my Snapchat e.c.t passwords to help with his trust issues insecurities.
We've been dating for almost a year so it's pretty serious.
Yes, I have broken his trust like in the beginning to 7 months, I've had my flirty moments but I've never gone as far as cheating. Since then I haven't talked to guys more than professional. He keeps on asking and asking..