He's asking Joseph to never let him forget that. Never let him forget that what he's doing is the worst thing one being can do to another. Joseph is the only person he can rely on here, and he knows how bad it's going to hurt Joseph, but he's praying that Joseph will trust him enough, and long enough, that he will be able to see his plan through to the end. Other than cleaning his room and(Later) helping him with the extraction of his own blood(Alexi's) for the breaking, Alexi is going to try and keep his direct involvement with the processes to a minimum. He's going to give Joseph permission to speak to Eric whenever he wants while Alexi's not with him, but I'm not sure how Joseph is going to take that news. For Alexi it is a show of trust, and a hope that perhaps Joseph will do Eric some good, but he's not exactly counting on it since he knows how Joseph feels about this whole thing.

In other words, it's good that he's conflicted. It will help greatly with the plan. Oh, and she's a little busy with school and stuff right now, but she plans to.