My 7yo won't stop asking why mommy and daddy aren't together

We've been separated for 8 months now. I keep giving the same answer—"mommy and daddy love you but don't love each other anymore"—but last week he asked again and literally started crying. My ex has been saying stuff like "your dad needed space" which isn't true at all. I'm trying to stay mature but this is getting to me. Any scripts that have worked for you guys that don't throw the other parent under the bus?