How do you share a passion with someone who doesn't understand? Climbing addicts try hard to spread the word – usually to their nearest and dearest, but sadly, often with disappointing results.

New lovers, fixated in the first flush of dotage, try hard to appreciate each others enthusiasms – as demonstrated by the amount of bewildered and confused young women seen at the bottom of crags belaying gnarly young men. I wonder how many of these hesitant belayers bother to continue with vertical play after the relationship has floundered. Although I did, there are plenty who don't and who are probably put off the whole thing – one man's passion can easily become one woman's cross to bear. In Portland recently I heard the death throes of a passion spread too far: 'At least look like you're interested in keeping me alive' said the fanatical male climber to the bored female belayer.

A family relationship is a different thing altogether. It's a cruel truth but it's rare to find offspring who will throw themselves willingly into anything their parents like. We (I'll come clean: I am a parent), can delude ourselves, but the reality is that too much enthusiasm is off-putting – especially when it's around anyone with a 'teen' in their age... It doesn't stop us trying though.

On a recent weekend trip to Bosigran the vain attempts of parents to spread the love were in full swing. There were different strategies, but they were equally failing. There was a group of new mums and dads with mewling babes hung on their chests, carefully picking their way through boulders with rucksacks on their backs laden with gear and nappies. They were going through that period of denial: 'This isn't going to change my life. My child will grow up to love climbing, to be great at it, because I shall carry on climbing and they shall come with me from the moment they open their eyes'. Passion by osmosis.

This parental ambition is misguided on many counts. They spent the day trying to climb, but each time there was an opportunity, the neediness of the vulnerable intervened to take priority. Welcome to parenthood where passion comes second place. And once these infants find their feet they'll start to discover their world, and there are a thousand things to find more interesting than a piece of hard vertical rock, so the chances of them finding it anywhere as attractive as you are a thousand to one.

I admit I was part of another family group guilty of trying to spread the love. I still hold the unspoken belief that one day my son will 'get' it. Foolishly I say to myself: 'he's got the right build for a climber; he's got potential.' I've tried not to be pushy – just extended an infrequent and casual invitation. Sometimes it's taken up and sometimes rejected out of hand. The amount of slaughter a teenager can perpetrate on 'Halo' is much more important than a mother's strange involvement with the outdoors and high places.

Parental ambition is insidious - and his ability to second an HVS this summer raised my misguided hopes (it also brought to my attention his fine command of the English expletive). But at Bosigran I almost ruined the future of anything resembling an occasional shared interest. A sunny day on the Cornish coast couldn't be unappreciated could it? He appreciated the sunshine (on his back on a slab, with eyes closed, plugged into his music) but he didn't appreciate 'Ledge Climb' one bit. The route book describes this V Diff as 'a pleasant climb'. We did it as a 3, with me climbing just behind him to help him though any problems.

We discovered at the start of the second pitch, where escaping wasn't really an option, that apparently chimney climbing isn't his thing. 'I can't do it', said the teenager, without a trace of doubt in his voice. I looked up at the belayer above us and grimaced. I wished our roles were reversed; teenagers respond so much better to people who aren't related to them. I racked my brains for

inspiration. What could I say except 'You have to'? – Exactly what not to say to a teenager. So I said it and it made no difference at all to his expression of fear, hatred and bloody-mindedness. I tried a different tack: 'You'll be fine. It's easy' – in full knowledge it wasn't. He still didn't move. Desperate times call for desperate measures. I grasped for anything ... 'If you get up there I'll get you a bottle of cider'. This under-age teenage carrot may have worked a bit because he stood up and went for it - admittedly with not the most positive of attitudes (dragged screaming and kicking is a more accurate description).The sound of his desperation was loud enough for other climbers to look at me with disapproval. Together again at the top, the parental guilt went into overdrive and I begged his forgiveness for ruining his life.

I had gone to Bosigran for the weekend with the intention of completing the 'Bosigan Ridge' – 8 pitches of entertaining V Diff climbing. Sunday had been planned for the assault, but after this crisis I reviewed the ambition. I had a novice with me and now a scared novice. If I was to be able to share the passion with him in the future a less stressful day was imperative.

It was a hard thing, although it shouldn't have been. I watched my usual climbing partner swarm up and down the peaks and troughs of the distant ridge while I belayed on 'In Between' (V Diff) and tried not to feel jealous. Instead I concentrated on the unseasonal warm sunshine, the turquoise sea and the fact I was spending a little bit of time doing something I love with someone I love. I recognised and appreciated the rarity of the moment. To keep mother and son apart I led the route while he was guided by an objective third party, and by the end of the day he didn't hate both me and climbing as much and confidence was mostly restored (I think. His confidence in my parenting skills was further reduced by the fact I reneged on my alcohol bribe – but then again I didn't promise did I?).

We desperately try to share our passion with lovers and family and sometimes it's embraced, but sometimes, despite everything we do to share our love of the activity, it's rejected. And what do we do then? With lovers it can end up being a matter or all or nothing; with family, our passion has to be negotiated and compromised. But I still hang on to the phantom of parental self-delusion and I'd like to think passion by osmosis can work. I know an E grade climber who describes how in his youth he was reluctantly dragged along to climbing venues by his enthusiastic mother. As soon as independence struck he turned his back on the sport – but returned to it in his own time and is now a passionate climber. There's hope yet then- but I won't rely on it happening soon.

About Sarah Flint (aka fishinwater)

Sarah writes a bit, climbs a lot and prefers to be outside rather than in some office staring at a computer. She got bored with her previous obsession, gardening, a few years ago, and found the strength and fitness developed in the 13 years she had been head gardener, suited climbing perfectly. Since then she's been greedy to cram as much climbing experience into her life as possible.

Where before she wrote about vegetables, she now likes to write about all things climbing and is keen to share the learning curve of her new addiction. She's based in the south west which is ideal for popping out to a crag before lunch and whenever the addiction calls.

She has a blog on climber.co.uk called 'Off the Wall', which is mostly about how not to climb.