"From what he's said he doesn't have much interest in hurting me." Of course Ianto talked to Tyki. It was the last thing he wanted to do and yet not something he could resist once he saw that video. Does he believe him? It's hard to say. He knows it was random last time so to an extent he does. But even still just the knowledge that he's here triggers a sense of dread in him, an expectation that he's going to round a corner any minute and find himself face to face with him.
"He mentioned being more interested in other people. I'm more frightened of him harming you or anyone else here than me." He knows how bad it is. He wouldn't wish that on anyone.