Really

Woman at Panera to her husband: Look, it's a guide dog.

Husband to Isaac: Hi there, fella! Look at those beautiful eyes!

Woman to her husband: I don't think you're supposed to bother them.

Husband: You're not supposed to touch them but you can talk to them.
 
Me: Actually you're not supposed to talk to them, either.

Man (looking confused): You're not?

Me: No. It distracts them when they are working.

Man: It does?

Me: Yes. Just like if you were at work and someone started talking to you and petting you.

Man: Petting I understand. But talking?

Me: Yes. It distracts them.

Man (looking doubtful): Really?