2 year old waking in the early hours

[CesareBorgiasUnicornMask]

Every night for the last week DS has woken up and come into bed with us at around 1am, which I have no issue with except he then doesn't go back to sleep! Until 5/6am-ish. He's generally very good - just lies there and periodically requests getting up or the iPad, which we refuse. We've tried taking him back to his bed and we've tried letting him stay - nothing seems to make a difference and it's driving me potty! Any ideas?

I would do rapid return. As soon as he gets up, immediately return back to bed. Repeat a million times the first night, half a million times the next night and a few thousand times the next few nights (I jest!). Eventually he will accept it.