See it is funny now but then I was just shocked

Thought I would share my end of term conversation with a woman from school. It seems a bit funny now - in fact it was my story of choice with the g&l friendly crowd I was out with on Saturday night and we all laughed about it. I even rang in and told it on the forum (when they discuss modern good manners) on 702 when a same sex parenting issue came up. But at the time I was, well, gob smacked.

I am used to people asking me how we got Al and/or who had him. And although at first I was a bit shocked by people's brazen-ness just walking up and asking - I have stopped saying 'same as you egg and sperm' or 'picked him up in woolies' and just started saying in as matter-of-fact tone that I can muster 'our beautiful boy was made with the help of IVF, Gaye carried him or (for kids) he grew in Gaye's tummy' sometimes I add 'he has a donor he can trace if he wants to when he is older' and sometimes I say 'she tried for such a long time to have him, he is a bit of a miracle' because I have decided that is what I want Al to hear about his conception and I want it to be matter-of-fact in his life. Not something curious, to be hidden or whatever.

Anyway...this day this woman let's call her MM (mother of boy- same age as Thomas- separated from his Dad) who has known me - through school pick ups for the past three years or so comes running up to me in the school yard one day. Apparently she ran into Gaye walking Thomas to school with Al the day before and so the next day when I am picking Thomas up with Al in my arms she comes running up to me and says 'so is this your little donor baby?' Can I just repeat that I was HOLDING the baby. He was in my arms in hearing of being called a 'donor baby'

I was speechless and I think my face must have dropped about ten kms. I certainly took two steps backwards and muttered something like 'erm this is my baby Al' she followed me reaching out for the baby saying 'oh yes of course he is yours too, don't get me wrong I have no problem with it I even thought of it for myself' (again how strange is it that people who hardly know you want to tell you that they are okay with your decision to have a child this way) I kept walking backward pulling Al close into me and said something like 'really' in, I imagine, a rather cold tone. She kept on 'I think it is amazing I have no problem with it' but my expression must have completely put her off and she quickly moved away when I made some excuse about needing to find Thomas' teacher. She has avoided me ever since - probably decided that I am rather oversensitive.

Afterwards I so wished I had said 'and how is your intercourse baby going anyway?' Anybody got any other good comebacks?