Note though to reiterate these domestic Italian overnight trains are older trains - shared WCs may be cruder so though in a private compartment you can have a romantic time it will not be in the lap of luxury perhaps.

WCs and douches in compartments are neat but also cost a heck of a lot more than those with communal ones. But still many will save over a night's hotel bill.

" you can have a romantic time it will not be in the lap "

What happens in your compartment stays in your compartment.