A fair few times now DH hasn't finished, he says I keep moving my legs a certain way and it puts him off and he doesn't finish.
If anything, he is normally a bit premature, it's a fairly recent change and it's a bit odd to me.
Today, it happened again, tried again a bit later but this time made sure I didn't move my legs and he finished.
Is this a thing? 
I'm a bit anxious that maybe he's actually bored/finding me not as attractive/kids have made me a bit loose etc and he's trying to save feelings maybe?