MIL minding the kids while we're at a sex club... the guilt is doing my head in

okay this is the one i never thought id be typing. MIL minds our two kids one saturday a month so my husband and i can have a "date night". what she doesnt know is that those nights are usually spent at a couples club in birmingham. she's 72, retired teacher, absolute angel, she thinks we're going for dinner and a film. the night itself is great but every time we get home and shes made the kids pancakes for breakfast and the house is spotless i feel like the worst daughter in law in the world. how do other parents in here handle this? do you tell yourself its just date night with extra steps? do you genuinely not feel guilty? im in my late thirties, the kids are 7 and 4, this part of our lives matters but so does the deceit. anyway. tell me im not alone please