We were all due to go out somewhere this evening and DS2 (aged almost 4) was playing up big time, decided at the last minute (probably my mistake that he didn't have enough warning) that he was tired and DS2 and I would stay behind.
Cue massive tantrum!
DS2 screaming "I want my Daddy, I want my Daddy" on and on and on, not listening to me at all, me having to shout over him ridiculous situation. I decided to leave him to it and sit downstairs until he had calmed down enough to talk to him. The screaming went on a good 20 mins or more (DS2 is very stubborn at times) when the doorbell went twice in rapid succession and then the door got rapped loudly. I went to the door to see my next door neighbour standing there (Victorian-semi so not paper thin walls, you shouldn't really hear much of your neighbour's noise through them). He asked if my DH was in, I said "No", he then said that he could hear DS2 screaming, could hear him saying "I want my Daddy, I want my Daddy" and he couldn't stand it anymore it is breaking his heart, he wondered if everything was OK. I explained that DH and DS1 had gone out, we were all due to go out but DS2 had been acting up and I decided to keep him at home hence the tantrum. He said again that it was upsetting him and asked me if I had locked him in his room 
, to which I said "no, in fact I don't think he is in his room anymore anyway, I think he is on the landing now but he has to calm down and that I have tried and failed to get him to stop screaming". He repeated that he couldn't stand it and wondered if he was OK to which I conceded I would go up and see him again. Of course I ended up pandering to DS2 a bit but did manage to calm him, think this was mostly because he was calming down himself prior to the neighbour calling. Of course neighbour will now think that DS2 calmed down because he came to the door and I went up to see to him. 
My question really is should I write a note to the neighbour, something along the lines of:-
Sorry we disturbed you this evening, DS2 was overtired and very upset and angry that his Daddy went out without him. I can assure you the crying distressed me too to the point I had a good cry after he was settled. However I felt I had no other option but to leave him to calm down a bit and was trying to follow the advice given by the childcare gurus in dealing with this sort of situation.
Sorry again.
Actually when I read it it sounds a bit lame, so open to further suggestions.
As a side note however I have had an evening disturbed by this neighbour as someone called at my door to tell me he was lying in his vestibule, did I know him and did I think he was OK, he then came to and we realised he was lying in a pool of urine, although there may be other reasons for this I think he is a drinker, although one with a very respectable front IYKWIM.