Hello my man :)
You're 21 now, welcome to my club haha! I want to keep this short and sweet. You're the best thing that has ever happened to me and I hope you feel the same way too. You're stronger than you think you are, smarter, wiser and most of all the most loving. You really have been patient with my mood swings and nonsense; despite all that, you still cherish and love me.
And I will too.
Please don't ever doubt that.
Happy birthday and have a wonderful day ahead :3
With much love all the way from London!
Serena.