Ever feel like a parrot?

Hello all!
The running theme this week has been 'no'. I must spend 90% of my time now saying "No Henry, don't take my phone." "No Henry, don't pull on my necklace." "No Henry, don't take Daddy's glasses off his face." He's become so used to it that instead of crying or looking upset, he peers up with his big blue eyes, gives you his naughtiest look and carries on!
For now, I don't mind. He's only 9 months, he's not doing any harm. But when do I start to really tell him off, so he knows what he is doing is wrong? Taking my phone and playing with it is one thing but when he's with other babies and tries to take the toys they're playing with, that's another. How do I explain to him that there's a difference? He can't talk yet, he only knows basic words like daddy and milk.
My fiancé doesn't understand what the issue is. He says there's plenty of time for him to grow up and to get told off and in a way, I agree with him. But what if Henry takes it too far and another parent tells him off? I'd want to kill them, then want to die of embarrassment and then wonder where I'd gone wrong.
If you've got any ideas/tips for me, please let me know!

In other news, we've had such a lovely weekend. It's the first whole weekend my fiancé has had off work in a long time so we just spent it together and relaxing. We went to a local park today, went round it's museum and had a picnic. The weather was beautiful and we were out in it for most of the day. It's really got me excited for the summer! I've got so many fun ideas for us to do when the weather is warmer. Henry was born in June so he spent the summer last year under wraps in case he got sun burn or heat rash!

Until next time
Shannon x