To be upset he left the kids but also that she's interfering?

[user1499779815]

Yesterday I got a message from one of the mum's I talk to on the school run. She said that in the playground at 9am she saw my husband who was dropping out 6 year old daughter off for school. She asked him if I was about because she wanted to borrow something from me. He replied that I was at home but she could walk back with him if she liked. They then both walked back to our house, which is actually next door to the school.
When they got to our house my husband opened the front door and it was clear at that stage that he'd left our 4 year old son in the front room watching telly along with his 18 month old baby sister. I was upstairs in bed, having my weekly lie in and completely unaware that the two younger kids were alone in the front room.
She said that she wanted me to know what he'd done and I thanked her for letting me know. Now I'm gutted, not only that my husband left our kids but above all that he allowed someone to witness this and call in to question our ability as responsible parents. I suspect that the other mum will now go and tell a few people in the school yard that we leave our children unattended and inevitably the story will evolve as it's passed down the line and turn in to something really awful.
My husband says that he was running late and so told our son to just watch telly for 5 minutes and mind his little sister. He was popping next door to the school and would be right back. If he needed anything Mummy was just upstairs. Apparently our little boy was quite happy to be left and when husband returned with friend both kids were just playing quietly and the door to the front room was still closed. He doesn't think it was a big deal because they are both very well behaved.
I've tried to explain to him that it's nothing to do with being good, anything could have happened in his absence, but he thinks I'm overreacting.
Also I can't help but feel slightly annoyed with the other mum, probably because she's unwittingly caught a glimpse of how our laid back approach to parenting has in fact turned out to be just laziness and irresponsibility. I know she'll probably gossip now and I'm so ashamed.
How would you all feel if your husband did this?

Your DH was wrong to leave the kids unsupervised, and should have woken you up. Having said that I'm not entirely sure why a grown adult 'needs' a lie in once a week. I am a WP and am up at 4:30 every weekday and 5:30 weekends. DH is the one who works from home but he's up by 6am everyday. Usually woken by the DC in both cases. Neither of us 'need' a lie in. It's a treat when it occurs (usually when DC oversleep) but we'd never do it deliberately unless one of us issick - it's not fair on the person left to handle the kids alone

Since women are usually the default carer, the vast majority of them do do it all alone.

And whoopie doo for you that you are both morning people. Many people like lie-ins precisely because they are not morning people. I get up at 6am on weekdays, to go to work. But in reality, I'm not a morning person. Weekends, I'm up late and to bed late, which suits my body clock better.

However, back to the OP. I think the OP has said she's discussed this with her DH, and it won't be happening again, so problem solved. I agree that this nosy woman is probably deflecting from her own issues, but at least the OP can just say she's talked with her DH if the issue is raised.