Chances are he will be fine, and all your worry will be for nothing!
:yeahthat: I'm sure he'll be fine. You'll probably suffer more than him

like Sloane said, if you're not ready, you don't have to leave him yet. But a 2 hour movie, and only 5 minutes away from him if he does need you, is a good place to start.

Good luck & enjoy your movie (what are you going to see?)

ETA - just re-read, your SIL wants to take him back home - you don't have to agree to that. Only if you're comfortable with it... 2 hours around a shopping centre, should be plenty to amuse him