He's amused at the feelings playing over Ianto's face, probably nothing that anybody else would pick up on as much as he does. Must not comment on it. Must not tease about Ianto looking like he wants to start firing off don't-touch-anything.
"I wouldn't mind but I worry about her being safe if security's compromised. As smart as our systems are, I don't think they're smart enough. Hmmm, yeah, it'd take awhile to get hundreds of settings back in."