Continuity mistake: When Grace and Leo accidentally meet each other in their apartment, ruining Will's surprise, they have a cuddle, then Leo walks over to the fridge. Between shots the back of his collar changes from folded down to folded up.
Revealing mistake: Will is reading a book in the total nude on the sofa, and then Leo walks in on him. When Will gets up from the sofa to run into the bathroom, you can blatantly see pants around his waist as he gets up from the sofa and runs to the bathroom.
Continuity mistake: When Karen and Jack are eating outside Jack's apartment on the small table, they both have plates of egg. Between shots during their conversation, the arrangement of the egg on their plates changes a few times.
Continuity mistake: When Will gets up from the sofa, as he speaks with Grace, a small white cushion with black dots all over it falls over on the sofa. In a following shot you can see that the cushion has now magically up righted itself.
Continuity mistake: After Will puts on his robe because Leo walks in, Will ties the robe straps so that one strap is much longer than the other one. During his conversation with Leo though, between shots, the straps suddenly both become the same length.
Revealing mistake: When Grace steps on the Dance Dance Revolution machine, she positions herself in a way it looks like she's playing on Double Mode, but the on-screen arrows in the game clearly show that she's playing on Single Mode.