Needy toddlers

I'm finding Ewan's neediness a double-edged sword at the moment. He's two-and-a-half now and going through a stage where everything is "Mummy do it" or "I want Mummy". If I so much as step out of the room it's "Where's Mummy?"
Thankfully, I do recognise this as a stage (otherwise it may be just too much to bear).
Every waking second (well, that's how it feels anyway) is spent with a small blond boy within arm's length, on my hip, sitting on my knee or even wrapped around my leg.
It's quite the invasion of personal space ... not that I'm not sure I even remember what that is.
Shaun comes into the kitchen to help me make E his dinner: "No Daddy! Mummy do it." Tears, flailing arms, wailing. Shaun tries to change E's nappy: "No Daddy! Mummy do it." Sunday is my allotted sleep-in day, but E wouldn't let Shaun make his breakfast, so I had to get up and do that then sneak back to bed when his back was turned. After which he stood, howling, at my bedroom door, trying to beat it down.
Of course, all this feeds into another issue: Shaun's response of "he wants you, he doesn't want me to do it".
Okay. How very convenient for him.
It's all very exhausting.
...
However ... I also know that this will pass. My sweet little boy will grow up (hopefully not too quickly) and suddenly I will no longer hold that privileged position of centre of his universe.
He will not want his mum all the time, he may even roll his eyes and push me away when I try to give him a hug. Probably just par for the course.
And so, I must try to remember this ... when the days are long and the attention seeking is intense, I will try to remember that it is a special thing we have. And not a burden at all...