The names have been changed to protect the innocent

Potty Mummy's sister here again. This evening I had a choice between topping up the hot water bottle that is the comforting task of updating PM's blog, OR jumping about in my (now too small) sports bra to Hannah Waterman's new fitness DVD. So, here I am.

Potty Mummy is fine, busy visiting the Moscow IKEA and discovering the delights of the Russian underground system. I don't mean that she's getting in touch with the dark underworld of a Muscovite crime network, I mean she's been on the metro. She hopes to be back on line by the end of the week.

So, back to the post. I forgot to mention a couple of incidents from the Christmas period which reminded me what it's like to be divorced. My son's father and I split about ten years ago now (a relief for both of us, I think) and I married my lovely new husband five years ago.

Incident Number One

My son had a major part in the school production of The Sound of Music. He invited his dad along to the performance. And his dad brought along his mother. She's slightly deaf and he's not one to pretty up his opinions to spare feelings, even those of children.

So I had the pleasure of spending the evening sitting on a small, hard school chair, in the dream company of my parents, husband, ex husband and ex mother in law. Ex Husband whispered expletives in my ear every few minutes. Ex Mother-In-Law shouted her opinions in the quiet moments, when the orchestra rested. Question - how many Exes does it take to enjoy a school orchestra tuning up for three hours? Answers on a postcard, please.

Incident Number Two

Before I remarried, I'd changed my name by deed poll back to my maiden name. I couldn't bring myself to change it when I married again. I suppose I should think about it now - after five years together, it looks like it might work out.

Anyway, this has all resulted in three different surnames for our little family. It's never been a problem for me, but appeared to be a problem for Canadian passport control officer when we arrived at Montreal airport for our ski trip before Christmas.

He couldn't accept that my son lived with us, despite the letter from my ex-husband granting me permission to take my child on holiday (don't get me started on that one), the copy of my son's birth certificate and a copy of my latest marriage certificate (Liz Taylor has nothing on me).

Silly me, I'd forgotten the copy of my decree nisi, the copy of my name change by deed poll, my last will and testament and that recipe for peanut butter brownies. After making me sweat for a few moments, he took my son to one side and questioned him about visiting his father, living with me and so on. Fortunately, my son didn't get flustered, answered correctly and we were granted the pleasure of continuing our holiday.

The same thing happened on our return, at Heathrow airport. Seven hours of flight socks and listening to Swiss Family Chav witter on behind us had made me a little grumpy. I think that the British passport official could see that he shouldn't mess with a woman with swollen calves and maple syrup cookie crumbs caught in her cleavage, so waved us through after asking a few half hearted questions.

I've been advised that, in future, I should have a permission letter from my ex husband, witnessed by a solicitor. The thought of going through that rigmarole makes me reach for another peanut butter and maple syrup brownie.