Dragged along on a camping trip

As the younger brother (27) and not really into the outdoors and in no relationship either my older brother insisted I join him and his family on their camping trip. Besides him was his wife and 2 children 4 & 2 and sister-in-law 24 a loner like me. I shouldn't have seen it coming as they were match making. Trying to get me and the sister-in-law to hook up, they had the help of our parents. So, I said I'll go along and at every opportunity we were seated together. I'm a loner but not as much as my sister-in-law's sister and when their youngest child got a rash, they left me and the sister to mind the campsite and we were alone overnight. Neither being the outdoor type, every sound was strange to us. So, were closer than we were before they left and slept in the same tent not in separate tents like before. I don't know if it was planned, but it worked, and I made a move on the sister, and she let me. So, we had sex and we they returned we were sitting so close to each other they knew, they had succeeded. In fact, we had to marry as we had taken no precautions and she got pregnant. But by the time she found out we were already in a full relationship and marriage was just the next step along. Also, we now have a liking of camping and a beautiful baby daughter to boot.