I don't think the students could ever think this would happen.
I've been teaching at my school now for several years. I teach what is called Core/General which is a combination of English and Social studies.
A few years ago, a new teacher joined our staff. For now, I'll call her Jenny. She is very good looking, though a bit overweight. Let me attempt to describe her. She is about 5'6', I'm guessing about 150 lbs., natural reddish blond hair and nice breasts that are perhaps 34b and very firm! I think she is about 31 years of age.
We have gotten along well in the three years she has been at the school and have joked quite a bit and even had some flirting. We are both married, she has one child, my wife and I have two.
Recently we were both in the lounge running copies for students and talking. The banter was getting charged with sexual overtones (something that was not unusual for most of our staff) and pretty soon I was starting to sport a bit of a boner. Jenny noticed and made a remark that my wife was gonna have to take care of that when I got home. I responded that I could hardly wait to 'take care of things.' I said maybe I should just slip into the restroom for a few minutes and '...take matters into my own hands.'
'I'd like to see that' she cracked, half joking I think.
'Anytime' was my reply also half joking, thinking that there would never be a chance of anything happening.
The mood seemed to change and Jenny replied, 'You realize only XXX has this prep period too and she never comes in here.'
Our lounge has a seperate restroom area with a door that leads to two unisex restrooms. When you are in either one, you can tell if the outer door is opened.
Quickly we slipped into one of the restrooms. They are fairly large because they are set up for handicap access.
I entered first with Jenny right behind me and she locked the door as soon as it hit the jamb. Then her hand went to my crotch and she said 'Well, let's see you take care of things' and she undid my zipper in a quick stroke.
'You too' I whispered and in about a half second she slid her pants and panties to her ankles. My cock came to full attention as I saw her very tightly trimmed red bush and her fingers began to rub her clit.
I dropped my pants and boxers to my ankles and gripped my cock and began stroking.
Perhaps it was the idea of a new partner or the idea that we were at work with over a thousand kids nearby but it didn't take long before I was on the verge of cumming and I told her so.
'Lemme see, lemme see' see blurted as her fingers tweaked her own pleasure point harder.
'Ahh...yeah....mmmm' I mumbled as I shot my load into my left hand.
'Niiiiice' Jenny groaned about 3 seconds later as she orgasamed too.
A quick wash at the sink, pull-up of pants and she slipped out. I waited about 5 seconds before flushing the toilet and exiting.
Soon we were both back by the Xerox and talking as if nothing had happened.
'So' asked Jenny, 'what are we going to do with Susie Q? Her last three tests were D's and F and she has missed four homework assignments.'
Ah kids, you think you are the only ones who masturbate? If you only knew!