How Mum put up with it for all those years I don't know. It got to the point where Sid was coming in through the cat flap. To evade detection, Sid told me, he used to scrub his private parts with carbolic soap before he came home - until Mum got wise to it and added carbolic soap to her list of incriminating smells.
When Mum died about six years ago, I thought Dad might do a Thomas Hardy and be all overcome with guilt and remorse about the way he had treated her. To be frank, I didn't expect a collection of love poems, but I did hope that her unexpected death might make him stop and think. Some hope of that, though. Sad to relate, the old goat couldn't even wait until after the funeral, and got off with one of Mum's distant cousins at the post-interment wine-and-twiglets do. I could have chinned him.
But I'm happy to say that he's got his comeuppance at last. He's fallen in love for the first time in his life, aged 71, and it has sent him into emotional turmoil. At last he's getting a taste of his own medicine.
For the past six months he's been seeing Veronica, a Spanish lady he met at a posh art gallery in Marbella. When Sid first introduced me to her, I must admit I quite fancied her myself. She's right out of the top drawer: mid-50s, fit, tanned, jet-black barnet, good legs, all the right bits and bobs, and moves well. And judging by all the tomfoolery hanging off her, she's not short of a quid or two either.
The night Sid introduced us, she offered me her hand in such a seductive manner, I could have wrapped her up and taken her home with me there and then. In fact (Sid would kill me if he ever found out), Veronica and I did get it together soon afterwards, after the three of us had had a boozy night out at Little- Eyed Dave's restaurant in Torremolinos. Unfortunately, I'd had a little too much to drink and we were both a bit ill.
At first I naturally assumed that Sid's relationship with Veronica was going to be as transient as all the others. The Four Fs and all that. But six months later Sid is totally smitten and reported by reliable sources to be following her around Marbella like a doting mallard.
This was confirmed when I received the first of a remarkable series of drunken, emotional phone calls from him. He sounded a complete mess.
"Son, I've never felt like this before," he said, weeping down the phone. "Every time I see her, me legs just turn to jelly."
"Have you thought about getting a Zimmer frame, Dad?" I said.
The following day he rang again.
"Son, I've asked Veronica to marry me and she's thinking it over," he said. "The tide's in her court, now," he added mysteriously - then he accidentally dropped his telephone by the sound of it and we were cut off.
And last week I was woken up in the middle of the night by yet another phone call from Marbella. This time Dad sounded jubilant.
"Son, she says yes! She says yes!" he yelled.
"Congratulations!" I said.
"But do us a favour son. Veronica says that after we are married, she wants you to call her 'Mum'."
"Call her Mum?" I said, aghast. "She's got to be having a laugh."
"Please, son. It's not much to ask."
"No," I said.
"Look here," said Sid. "As well as being the light of my life, Veronica is worth over a hundred grand. Surely you can bloody well call her 'Mum' for a hundred grand.
"Just look at it like an investment."
I said I'd think about it.