Howard Jacobson: We debase our cherished relationships with every mindless 'love you'

Love you." "Love you." Well it's Christmas. If you can't tell people you love them at Christmas, when can you? Allow me to make a stab at answering that: how about never?

Never, outside the bed, I mean. Never except in the arms of the person you love romantically, erotically, madly, deeply. And even then not quite so often as it would seem, from watching bed scenes on television and in movies, that people now routinely do. One day my objection to "Love you", "Love you" will be shown to have scientific justification. Every time we exchange a redundant "Love you" we warm up the planet. Five "love yous" a day will turn out to be the equivalent of leaving every light on in your house for a week, or flying to the Copenhagen climate conference in a private jet.

In the meantime I can cite only aesthetico-moral objections to saying "Love you". It lacks euphony, it lacks beauty, it conceals what we truly (madly, deeply) feel, especially from ourselves, and it has the opposite effect to the one we intend. Say "Love you", "Love you" often enough and you will eventually get to "Hate you", "Hate you".

Let me give you a macabre instance of this – and why are we drawn to the macabre at Christmas if not in revolt against false sentiment? Laura Lundquist and Elizabeth Barrow, aged 98 and 100 respectively, were residents of Brandon Woods nursing home situated near Bliss Corner – I kid you not – Massachusetts. They had shared a room for a year. According to nursing home staff they acted like sisters, walking everywhere together, taking lunch together, and each saying to the other, "Goodnight, I love you", before turning out the lights and going beddy bye-byes. Love you. Love you. And then guess what happened?

In the tradition of the best macabre story-telling, I'll keep you waiting, but here's a hint – it involves a plastic bag.

We didn't do "Love you", "Love you" when I was growing up. We didn't tell our mothers we loved them and they didn't say they loved us. I told Gladys who worked on the pet counter at Boots that I loved her, but that was a lie to inveigle her into the back seat of my father's Dormobile. I didn't, by the way, tell my father I loved him when he loaned me the Dormobile. "Thank you, father" was considered adequate in those days. Nor did Gladys say she loved me. She didn't get into the back of the Dormobile either, for those interested in the progress of this adventure. But she did get into the backs of all the Dormobiles of all my friends. When I asked her why them and not me she explained that none of them had told her they loved her. This was an early lesson, for which I am eternally grateful, a) in the virtue of telling the truth, and b) in the trouble saying "Love you" can land you in.

But I still believe I was right to try on with Gladys what I wouldn't have considered trying on with anyone who was not a girlfriend. One kind of love is not another. Love felt is not necessarily love declared, and vice versa. And a reserved non-speaking love is often the deepest love of all. In our decision not to speak it we acknowledge the profound unsayability of some of our most complex emotions. Our society's promiscuity with the language of affection is part of the disrespectful delusion that there is something accessibly lovable in all of us, a sweet and needy mutuality which a word like "love" will trigger.

So back we go, then, to Bliss Corner, Massachusetts, where, if you listen carefully you can hear the Atlantic Ocean rolling into Buzzards Bay, and where, it is alleged, Laura Lundquist says "Goodnight, I love you" to Elizabeth Barrow, puts a plastic bag over her head, and ties it with a little bow. Night, night.

You could argue that someone should have seen this coming. According to her attorney, Laura Lundquist had "issues of cognitive impairment". She had been complaining about the number of visitors her friend had been receiving. She had several times accused Elizabeth Barrow of "taking over the room" and had taken to blocking her entry to the bathroom with a table and then punching nurses who tried to move it. But nothing could seriously have been amiss, could it, between two sweet old ladies, aged 98 and 100 respectively, who went around like sisters and said "Love you", "Love you" every night?

We'd do better admitting how much we want to murder one another before turning off the lights. At least that way we'd be honouring the demons in ourselves and reminding others to keep their wits about them and maybe take a pair of scissors into bed. What's the betting Tiger Woods said "love you" to his wife each night, either underneath their marital coverlet, or down the phone from the 18th hole? Given our surprise at what continues to be unearthed, he might have said "Love you" to us as well – and no doubt, in some cases, did.

But what business do we have being surprised at all? Tiger Woods gloried, for his sponsors, in a wholesome image. That's where the lie begins. Not in the man but in the image. There is no such thing as wholesomeness. You can put up a fight, you can fast and say your prayers, you can go into the desert and scourge your flesh, but that doesn't make you more wholesome, it only makes you an unwholesome man wanting not to be a man at all. There is no mystery in Tiger Wood's behaviour. He did what he did because he could, and because unimaginable success and wealth, garnered on the back of a tiny talent for time-wasting – golf being a game which attests to the emptiness of life like no other – left him with nowhere else to go.

Sex, after a certain age (age excused my lie to Gladys, I think), is three quarters idleness. The phallus with which men play as children – when "A foolish thing was but a toy" – they continue to play with, in moments of boredom, until they die. It's a reliable resource when life yawns. And if you are away from home a lot, wreathed in the unreality of fame, and can easily persuade the fame-mad to play with it for you, so much the better. That men in the phallic professions – guitarists, golfers – will turn to this resource sooner than the rest of us needs no explaining or excusing. Ecce homo.

In the meantime, reader, this being Christmas, love you.