I have bought DS1 (12) an alarm clock...

[SoupDragon]

I have set it to call his name gently a couple of times and then bellow "DS1! WAKE UP!"

Now, do I just hide it in his room and not tell him or fess up?

dont tell him!

Definitely don't tell him but please let us know the reaction

Oh good - that was my gut reaction too.

how did it go this morning?

Sadly, he found it last night [grrr]

On the plus side, he couldn't work out how to switch it off so it bellowed at him every 5 minutes.