I'd like to configure Google Play so that it doesn't update applications when I'm using my phone (Samsung Galaxy S3) or tablet (Nexus 7).
Note that I still want to have the auto-update, but only when I'm not using the phone.
Here, for example, is a suggestion for a Tasker profile that enables auto update only when the device is plugged in for charging. You may be able to find an alternative trigger that better suits your needs, like screen off, etc.
Or you can use Greenify to hibernate google pay store and services.(only if your phone is rooted.)