Lol if this were on DadsNet you'd be red-flagged like crazy!
-You snooped in a box you KNEW was his, knew was probably yours and invaded his privacy. Here on MN women would be saying he invaded your privacy, that's controlling behaviour, he doesn't trust you, he has no respect for you etc...
-He spent way over the £10 limit to surprise you and you're being majorly ungrateful, ESPECIALLY when he earns less than you and this money probably was harder to obtain
-He actually took the time and effort to shop WAY in advance at a place he knew you liked, meaning he's a genuinely thoughtful and nice guy
-You call him an emotional robot, meaning you technically see yourself as superior
-Yet you know you have a catch, but belittle him???
-You're amazingly hypocritical and hard work because here he spent over the limit (your orders), and you're upset he went against it... but then told him prior NOT to do anything on your birthday AND HE DIDN'T (following your orders) and you got pissy with him???
-He prioritises you over his own mother, I.e. he remembers your birthday and spends excessively for Christmas on you but disregards her's
So, constructive comments... don't tell him. He'll feel violated as he rightly should. It was his space, in a box you knew would be for you. You knew what you were doing and you knew it was wrong. He'll be thinking what else has she been doing, what else has she found, does she go through my stuff routinely??? You want to keep up this facade of being a nice person, act sweet and grateful on the day you receive it. Ask any woman, any online survey, what they look for as number one when it comes to men and that is usually trust. It should go both ways.
BTW, these aren't all my thoughts, I'm actually paralleling the responses I've seen when a similar situation occurred with the genders reversed on MN. :)