Anyone for Tennis?

Jane is overweight. She knows this. Her 5 year old son told her yesterday; while they were standing in the checkout line at the grocery store. He also told the other 7 people who were waiting in line with them, the girl behind the register, and anyone else who happened to be within hearing distance.
Jane's fellow shoppers smiled at her, and an old lady (stick thin ... lots of celery and fresh parsley in her basket) ruffled Ben's hair and tickled him in the ribs and pretended to ignore the slabs of chocolate and the doughnuts, pastries and chips that filled her cart.

And then this morning She found her 9 year old daughter crying. Fearful of bullying, child molesters, or early onset puberty, Jane was at once the concerned attentive Mother she reads about in all the parenting books. But it was her she was crying about. In school health class they had learned about obesity and heart disease and death, and she was mourning her potential orphaned status. As Jane attempted to staunch the stream of tears and snot she explained that Mummy wasn't actually obese, just a little on the chubby side. Through subsiding sobs, Sara asked what her B.M.I was. Jane confessed that she wasn't sure. She didn't confess that she had no clue what a B.M.I was. One doesn't let ones children think they know more than their parents.
Mentally furious with the school for upsetting her little girl, Jane mopped Sara's face, cuddled her close and told her not to be frightened. She wasn't going anywhere. She'd be there for her always.
But once she was in school, and Ben had been bundled off to preschool, Jane googled B.M.I. Then she took off her clothes and stood in front of the full length mirror in her bedroom. Then she returned to the computer and googled "tennis lessons".

And now here she stands, baggy sweats concealing folds of flab. Trusty old Wilson racket, unused since college, held limply in her right hand, staring in open mouthed wonder at the vision before her. Check out that Body Mass Index!
His name is Jack. He's 29 years old. And he is her personal, her very own, one on one tennis coach. Let the lesson begin!

An hour later she is lying face down on the court. She knows that her cheeks are bright purple. She can feel a vein throbbing steadily in her forehead. She is a shaking, gasping mass of sweaty blubber. She is vaguely aware, though she refuses to open her eyes, of Jack crouching beside her. Thankfully he seems to understand that in her mortified state Jane is unable to converse, so they lie and sit in what could almost pass for companionable silence as seconds stretch into minutes. Somewhere in the background children are playing on the swings. Birds are calling in the nearby trees. Her heart rate gradually slows; the shakes become twitches. Jack breathes an audible sigh of relief, probably thankful that he listened to her wheezing protestations and didn't call the emergency services. Paramedics on the tennis courts aren't good for business. But she is not dying. She is merely ... grotesquely unfit.

That evening, Jane tells her husband about her day. She shares with him a trip to the pet store to buy dog food. She shows him her manicure, and he murmurs appreciatively at the choice of color (Groovy Tangerine). He helps Sara with her homework as Jane runs a bubble bath for Ben, and as Mark reads their son a story, she hugs Sara goodnight, and reassure her again that Mummy will still be here tomorrow.

Later, over a glass of wine, she almost tells Mark about the tennis lesson. She almost confesses the embarrassment of collapsing like a giant purple blancmange. She almost tells him she has signed up for a further 10 lessons. But she doesn't. And she's not quite sure why not.