All little boys go through a "mummy" stage, and i think this is what he is doing. He is aware that there a whole big place out there now, and he is safest with mum. He will go forth a happy little camper in time, if he has mums security. I beleive you are doing the right thing. A content, safe, child will eventually venture off, he wont stay stuck to you forever!! And get ready for when dad becomes the main sorce of security and comfort, your heart will break!! But he will always come back to mum!! A child cant be spoilt with security, love and play time!!! It can be hard and frustrating, (carting your toddler to the loo with you etc ,) but he'll grow out of it....eventually....