I know my son is a smoker, but he's refusing to admit it to me

As a mum of four, there are many, many things I don't have much time for: cleaning skirting boards, matching socks and making soup from scratch to name but three.

However, if there's one thing that really grinds my gears, it's when my children tell tales on each other.

Yes, if one of you requires medical attention, then by all means point a finger at the perp and allow them to take their punishment, but if your younger sibling momentarily hides the remote then handle it yourself and leave me to deal with the rest of our household chaos.

So, while I've always encouraged my children to handle minor matters between themselves, they do know that certain issues definitely require mum's imput – the fact that one of them is now a smoker, for example.

Yes, last weekend I learned, through my 13-year-old daughter, that my 15-year-old son smokes “on the daily.”

Given that Rebecca is prone to dramatics - and what 13-year-old girl isn't? – I knew I needed to clarify and confirm facts before dropping to my knees and weeping for my son's stupidity.

“He smokes every day, Mum” she insisted. “I see him every single break-time, I swear. Him and his mates.”

I tried to regulate my breathing as my mind raced.

Had I, on some level, known and turned a blind eye?

Had I not done enough to warn him against the dangers of smoking?

I mean, he watched his grandfather die from lung cancer when he was nine, surely that would have been enough to dissuade him from ever lighting up.

Rebecca pleaded with me not to tell him she had “ratted”.

“I won't,” I promised as I swatted her away and attempted to gather my thoughts.

“How should I approach this?” I wondered as I mindlessly moved items from one area of the kitchen to the next before absentmindedly putting them back.

Chris was no angel, but I genuiunely expected him to have more sense when it came to smoking.

I spent the rest of the day waiting for him to arrive home so we could sit down and talk, but every time I imagined how the conversation might go, my blood boiled that we had found ourselves in this position.

Suffice to say, he denied it outright and demanded to know why I was accusing him.

Omitting the fact his sister had a role in the big reveal, I rallied and said I had smelled smoke off him.

“It's my mates. They smoke. That's what you smell,” he lied.

I pictured him as a toddler, a smiley seven-year-old and a shy 12-year-old and vowed he wouldn't endure the same devastating end his grandfather had experienced.

“Chris, I know you're smoking and I'm giving you the opportunity to stop now without being punished.”

“You don't know what you're talking about,”he muttered before leaving the house in a huff.

And that's how the last week has played out: accusations, denials, accustaions, denials.

What do I do?