So, imagine you are 14, feeling supercool, swinging down the corridor with your friends. Who do you bump into as you take the corner? Your mum (or dad). That's the hazard with having a parent who is a teacher. You can pity the Year 9 girl with her skirt turned over trendily at the waist or the boy with his shirt out and hair gelled skywards. They - and their friends - know this particular teacher saw them in their brushed cotton pyjamas only a few hours earlier.
It is awkward for the parent too. But the almost inevitable decision is do you teach at your child's school (or do they go to the school where you teach) or make sure that the family generations never meet professionally?
"When they're little it's rather nice for both of you," says Year 1 teacher Helen Hayes, whose two children have both been through her Dorset primary school. "Little children like to see their mums and I liked knowing they were fine.
"But when they get older it's hard all round, particularly for the children. My husband is a deputy head in a secondary school and we're very grateful it's not the nearest school.
"By Year 5 it's beginning to get awkward, particularly if the child is the sort - as my second one was - who has the odd brush with staff, in other words with your colleagues."
Unfortunately, it seems teachers' children often are that sort, at least when they all go to the same school. Retired headteacher Ruth Shaw believes it is to do with the natural adolescent need to establish a certain amount of independence from parents.
"School really is their world. It's their social group. You only have to read the Adrian Mole books to know that home is just a backdrop - a potentially embarrassing one at that.
"They can be themselves with their friends, develop their personalities. At school they have their own codes, their own frame of reference, even language.
"If you drop into that territory the person who has authority over them at home, the person who sees them in their jim-jams, they feel horribly watched and restricted. It's not that they want to do anything dreadful; in fact they are more likely to get into trouble if you're around because they're feeling they have no space of their own.
"It's something I always discouraged among my staff. Put somewhere else down as your preference and give both of you a break, I used to say.
"Just having a teacher for a parent can be annoying enough for some children: you know too much about their daily life for their liking. Having a parent at the same school can be inhibiting and embarrassing.
"If there is really no choice because all the other schools within reach are oversubscribed, at least try to make sure you don't end up actually teaching your child."
There is no special provision for teachers' children in the criteria for oversubscription in the school admissions code of practice. Like other parents, teachers can express a preference, no more.
However, many prefer to send their children to the school where they teach.If it is an independent school, fees may be reduced for children of staff. Often it is because life's timetable is much simpler if everyone is going the same way in the morning. Or you may simply feel your school is better than the other options.
"It's not worth it," says Mrs Shaw. "You have to ask yourself how well your child will achieve if he, or she, spends a lot of time wishing you weren't there.
"There's also the question of your own professional personality. You may not want half of Year 9 coming around on Saturdays to hang out with your son while you're flopping around the house in leggings.
"Of course, you can avoid teaching that particular group if you're lucky, but it can still drive a wedge between you and staff who do."
It can inhibit colleagues from treating your child just like any other child. It is harder for them to sound off in the staffroom, harder to talk about the case with other staff members. The situation is bad enough if the parent recognises the problem, even worse if he or she insists a colleague is deficient. It is undermining for colleagues to think the child and you may be discussing "that awful teacher" over tea in the kitchen.
Geography plays a part in decisions about schools. Deliberately driving your child miles away from the village primary where you teach before driving yourself back again is probably not worth the strain. In a town with a choice of secondaries, though, it may help family relations to opt for another one.
There are other considerations. A mother at one of my children's schools explained why she had chosen to send her 11-year-old daughter to the school where she taught history, rather than the one where she had been expecting to go.
"My husband had left home. It wasn't expected. We were both utterly devastated.
"She was in desperate need of stability: new school, divorcing parents, enforced house move. Her whole life was upside down and she was weepy and depressed. I wasn't feeling anything like strong enough to buoy her up. So I talked to the head of our school, who said there was space. The local authority had no trouble with the change. It meant we could see each other during the day. Just passing in the corridor was some sort of support. For both of us, actually.
"It was never really a problem for either of us or - as far as I know - for my colleagues. It's a big school and I never had to teach her. She was able to focus on her work because she wasn't worried about me and that meant she wasn't a problem pupil. She's moved on to sixth form college now.
"For us it was the best thing. I felt lucky I was in teaching."
If you do feel the need to have your poppet in close proximity, do not expect to get preferential treatment. Last year the schools adjudicator, David Newton, ruled that Lewisham should not give preference to children at the schools where their parents taught. The authority had used preferential selection as a recruitment incentive, but the adjudicator said it discriminated on grounds of parental occupation and possibly on race grounds too.
Anecdotally, though, one still hears of authorities being sympathetic to teachers who want their children to go to another school. But oversubscribed schools are wary of stretching the admissions code.
Teaching your colleagues' kids, page 2
School admissions code of practice www.dfes.gov.uksacodeOffice of the Schools Adjudicator www.schoolsadjudicator.gov.uk