Husband not flushing the toilet. AIBU?

[SchoolGossipWoes]

My husband never flushes the (downstairs) toilet at night. This results in a pan-full of very smelly urine in the morning (he usually stays up later than me and does a few wees in there before coming to bed). It's truly disgusting and he won't stop doing it.
I got home from school and grocery run this morning (at around 10am) and as I walked past the downstairs toilet door, the smell hit me. The smell inside was horrific! (not envy)
His reasons for not flushing range from not wanting to wake the children (it doesn't) to just "forgetting".
Please help mumsnetters, AIBU to find this disgusting and if so what can I do to make him stop doing this?

I went to stay with a friend thinking it would be a lovely break. Night one, she said no flushing the loo after 7pm for wees incase in wakes the kids. The toilets stank of old pee. I was on my period so flushed, after my second grilling about why I needed to flush the toilet at night I booked a hotel. I'm all for saving water but that's too much for me.

I'd be handing him a pair of rubber gloves and sending him in to clean the loo everytime he left it like that.

So he hardly drinks anything and his wee smells strong and unpleasant, yet he's weeing multiple times in an evening.

Are you sure he doesn't have a UTI.

I drink a fair amount during the course of the day, probably more than I need to really, but very rarely need to wee in the evening and I'm a fairly old woman.

Sounds like he might need to get that smelly wee checked out.

And he needs to flush the loo.

Does he wipe the toilet rim after splashing it with urine?
Does he wash his hands after using the toilet?

Make it his job to clean the downstairs toilet. It leaves a horrible brown stain.