All the years I’d kept Shannon from having a puppy because I knew it would pee on my carpet, claw my furniture and chew my shoes, I never knew it would be so invaluable for teaching that most important high school lesson — abstinence.

Trust me, and I’m sure any parent of a teen would agree, the consequences-of-sex lesson is worth every pair of shoes and one-of-a-kind family heirloom our new puppy has digested over the last three weeks.

Despite early heartfelt promises — “I’ll feed her. I’ll walk her every day. Pleasepleasepleasepleasepleasepleasepleasepleaseplease let me keep her.” — after just two weeks with her beagle puppy Lucy, Shannon had grown weary of the responsibilities of being a “parent.”

She no longer liked being awakened at 5 a.m., especially in summer when sleepovers might keep her up until 2. She no longer liked scrubbing yellow stains from the carpet or having her feet continually damp from being licked.

Still, she diligently walked and fed and played and made a good puppy mama. But before long, our house began to sound like the toy aisle in Walmart: “No, Lucy.” “Put that down!” “How did you manage to fit that in your mouth?” “If you do that again, I’ll …” “Get that Tinkertoy out of your nose.”

Well, that last one, maybe not so much.

Shannon began to appear tired.

Her clothes looked worn and slept in.

Oh, they were.

Any-hoo. She began to smell of kibble and pat her boyfriend on the head.

The strain was showing.

But she wasn’t ready to admit parenting Lucy was too much for her.

Not even when Lucy:

• chewed one heel of each of three pairs of my good shoes;

• shredded the underside of the upholstered chair in the living room;