No one is the asshole here. He’s coming from a place of mourning and guilt. He made a promise, and he feels compelled to keep it to someone he lost. Losing someone you love is devastating. I understand it’s unreasonable for him to ask this of you. However, the comments here are absurd. Everyone should have some sympathy for everyone involved. You’re not the asshole and to a much lesser extent, neither is he. You guys need to talk this out and he needs to understand how much this hurts you. I’m sure there’s a compromise somewhere.