A lucky escape

In 1960 we moved to Luanda, Angola, and I had my 7th birthday not long after we arrived there, my sister being just under 2 years older than me, so was 9 that April. We first lived in a house on the outskirts of Luanda, but due to security worries we moved to a more central location a block back from the sand cliffs called Barrocas. 
One day while we were playing in the garden a man in uniform appeared at the gate and asked if he could speak to our mother. Mum came out and he explained that he was in the Portuguese airforce and stationed in Luanda, and he was walking past and heard us speaking English, and wondered if my mother would allow him to spend some time with the family to practice his English, and also as he missed his own family back in Portugal. He was around 30, I guess, and very well spoken, and showed Mum his airforce ID, so she invited him in for a coffee and a chat.
He used to come round once a week or so and we would go for a walk with him round our neighbourhood, usually ending up at the open-air Miramar, cliff-top cinema where he would buy us a Coke. He even took us back to his barracks in the centre of Luanda, and showed us around, promising to take us to see the actual airforce planes one day. It all seemed so innocent back then - he was always polite, always in uniform, always insisted on talking to Mum before we went out with him, and always let her know where we would be going.
One day, however, after we had known him for about a year, he came round and my sister wasn't able to join us - I cannot remember if she was unwell, or staying with friends - so I went with him alone for a walk, an 8 year old with a 30 year old unrelated man! We headed towards the Barrocas, the sandy cliffs, and he took me a little way along a path into the bushes where we had a great view across the bay. He told me he loved to come here for some peace and quiet and to admire the view, but that he also used to bring his "girlfriends" to this spot as it was secluded. He asked me if I knew what he meant by that, and though I was so young I had a very good idea what he was talking about (I had a friend the same age as me who was rather precocious and he had told me a lot of things I probably shouldn't have known about at that age back then, and though I didn't fully understand a lot of it I was aware of what males and females got up to - though not really sure why!). He then went on to tell me that he hoped to bring my sister there one day - who was now 10 years old! He then said he needed to urinate, and while doing it said how hot he was "down there" and how this talk had excited him a little. Nothing further happened (honestly!) and we went home.
Despite my youth and inexperience I knew that I had just witnessed something that was very wrong, so told my parents about it when I got home, who immediately cut off all contact with him. I am not sure if they contacted the airforce, but he never came round again. Looking back I am surprised I had the sense and courage to tell my parents, as I was an extremely shy child, but just knew that it was the right thing to do, and that it probably averted something very serious.
In hindsight It was very foolish to allow a relative "stranger" such access to 2 young children, but back then times were very different and we were not so aware of the dangers of predatory adults, plus he had not shown any indication of other than honourable intentions until that day. I still regard that as a very lucky escape.