Marina's overcautious mum tended to shield her"delicate flower" from all things amorous...
As we all know [as does Marina] her "warnings" became legendary !!!.......
I think all rooms would have been booby trapped.......and the weekly grass cutting by Marina's biggest fan between March and September would have been allowed,as long as "mother" was positioned in her deckchair,all eagle eyed with her glass of orange squash.
Resistance would be futile....and at the end of the day,I feel Marina respected her mum so much she would not think of inviting Howard inside !!.