Visible crew/equipment: When Jack is explaining to Will how to visualize someone else while kissing them, you can briefly see a blue mat in the bottom right corner of the screen. This is where Karen later faints.
Continuity mistake: After Grace tells Will he has to go on a second date with Nathan, she runs out onto the terrace to hide. When she comes back into the kitchen, she leaves the terrace door open. In the next shot it's closed, the open again.