Several other mums that I know or am friends with are nice enough, but cannot hold a conversation with another adult without their children butting in over and over again.
If I'm talking and my kids butt in, I make them wait until I've finished my conversation, unless it's urgent. Some other mums will immediately halt the conversation, see to their child if it makes the tiniest sound, then back to the conversation, just get back on topic and child utters another word, so back to the children again, and so on, until the original subject of the conversation is completely forgotten.
Very irritating!