First time with older guy

I was 18, I met a older guy about 50 at a pub we used to visit, he was really a nice guy, he bought us drinks and made us laugh alot, after spending the evening with him he asked us to spend the weekend at his weekender on the the shores of a lake north of Sydney, We talked about it and agreed to go with him, i was with 3 other mates, It was a great spot right on the lake front, nothing happened that night we all got drunk, the next day we had a ball, swimming and using his tinny and canoes , we went to the local fair and had a lot of fun, that night we all had too much to drink and finally went to bed, 2 mates slept in the second bedroom and I and and a mate slept in the main bedroom with the older guy, in the main bedroom was a single bed and a double bed, I had the single bed my mate shared the double bed with the older guy, about a hour after we went to bed I was woken buy moans from my mate, I listened closely and realised they were having sex, I got up and looked to see what was happening, they were both naked and after seeing me watching them asked me to join them, I removed my shorts and joined them on the bed, we sucked each other and the older guy had anal with both of us, he then told us to fuck each other, it was a fantastic night, the next night we swapped with our other 2 mates, we all met with the older guy at his weekender for the next couple of years, It was a great time.