Question about the premise
I've seen the first series, but not any more. As anyone who's seen the remake can guess, they admit to Mrs. Roper that they lied about Robin being gay.
After Chrissy's mother arrives however, she doesn't mention being told he's gay (in opposition to the American remake). Then in episode four, every time the Ropers see Robin, he's bringing a different lady up to his flat (without them seeing the other ladies leave, if they indeed did; it's been a while), and they both have pretty much the same reaction.
So, did they ever use the lie-about-being-gay stuff again?