And why do I always get a chatty taxi driver when I’m too upset to string words together and just want to be left alone? I mean, do I inflict endless boring stories about my childhood holidays by the seaside on hapless, distraught strangers? No, I do not!

The moment I got home I phoned Sergei and told him I knew all about his and Linny’s affair because I’d just seen her in the blue butterfly mask, although this time mercifully clothed, and how could he possibly do that to me with my best friend?

And he said he hadn’t had a relationship with anyone other than me, especially with Linny, who clearly didn’t understand the artistic temperament, and I was his only beloved, as he’d shown me today, and he couldn’t live without me.

‘And so we should put the past all behind us, Tsarina, because these little incidents mean nothing to me compared to our so-great love.’

Obviously, he saw a clear distinction between our love affair and recreational sex, which I couldn’t, especially when it was with my best friend.

However, he wouldn’t straight-out admit it, so I said I was going to see Linny next morning and get the truth from her if he wouldn’t tell me. I put the phone down on him while he was still being persuasive in his wonderfully sexy voice.

Some diehard little piece of me still hoped that Linny would convince me that it wasn’t her, but the rest of me was shell-shocked, cold and shaking, and if this was a nightmare I’d like to wake up from it.

Early the next morning I penned a wonderful chapter of The Orchid Huntress, full of love, betrayal and very organic sex, after which I caught the train into London and burst in upon an unsuspecting Linny.

Her smile of welcome wavered when she saw my face, and then vanished completely, to be replaced with one of absolute horror when I said without any preamble: ‘I know you were the butterfly-masked lover in Sergei’s flat that time. I realized it when I saw you wearing that blue mask again last night, and how could you? My best friend with my lover!’

She burst into a Niagara of tears and denied it between sobs rather incoherently, and told me she didn’t like him anyway, and would she do that to her best friend? And I said, well, would she?

Then she completely broke down and wailed, ‘I only wanted to show him my Venetian mask. I’d seen his collection hanging on the wall that time I took the note round for you, and I thought he’d be interested.’

‘Yes, but did you have to show him the mask in the nude?’