He studied her for a moment, but he didn't see anything in her expression to indicate she was attempting to pull a fast one on him. Now he just had to channel his inner Regis..

"When I said I'd be careful not to serve you something harmful at my bar. I realize things got messed up the last few times you and I spoke, but I'm trying here. Wouldn't a more respectful answer been to say something positive back or 'thank you' rather than say you definitely won't be going to the place I just invited you to."