Grinningly

Squeaker's dog sniffed and barked joyfully around them till his licking efforts to bottom a salmon tin sent him careering in a muzzled frenzy, that caused the younger woman's thick lips to part grinningly till he came too close.

It’s very funny — Bob is played by Bill Murray at his most unhinged, the psychiatrist by Richard Dreyfuss at his most grinningly uptight — but it’s a little creepy too.