When he complains about his wife, do you want to give the impression that you are different to her and would never behave in the way complained about?
Do you sometimes check yourself and realise you're giving a false impression of your marriage and your husband?
Did you used to talk about him a lot at home and have stopped doing that so much recently?
Do you make more efforts with your appearance at work?
Do you find yourself wondering whether there will be an opportunity for something to happen, like a works do, a 'friendly coffee' or drink after work, or even a conference/course you could both attend?
Are you hoping he will send you a Valentine's card or message?
Do you text or communicate outside of school and are you feeling bereft now it is half term?
Are you finding that your husband irritates you more than usual and that you are looking for things to be angry about?
What would you say in response if the teacher told you he found you very attractive and 'if things were different......'?
These might be some good questions to ask as they'll show you how your boundaries might have slipped without even realising it consciously.
Would you talk to your husband? Go beyond the typical normal response to that question, which is: "Good god no, I couldn't hurt him like that" and delve a bit deeper. Could the reason be "God no, if I told him, this would have to stop and I'm not ready to give it up yet."