It's to Richie's benefit because Grace is charmed. Alex lied to her for so long that people being honest with her, even if they think they've out their foot all the way in their mouths, is always better than the alternative.

"Don't worry about it. And for the record, if someone mentions their horrible scar and then you look at it? That's on them, not you."

She brought that on herself! She is self-aware!