I wrote:
I read an interview somewhere -- and I wish now I could remember where,
Well, I just went and looked, and, amazingly, I actually found it! It's from an interview with JP that appeared in "Down & Unsafe #4." Here's what she had to say:
"When I went into rehersals one day - in the third series, I think - Steven Pacey said to me, 'Why are you looking so happy?' I said 'I'm happy because I've just moved. I'm now living on a houseboat in Chelsea.' He went chalk white and said, '*I* live on a houseboat in Chelsea!' and I said, 'Gosh, Stevie, I'm the girl next door!' He said, 'If *you* were the girl next door, I'd move!' and he did! [laughter] I told Tanith Lee about that conversation and she wrote it into the script so Steven and I had great fun playing that scene."
So there you have it: the official answer!