Psychologists say our sexual arousal predilections are imprinted during adolescence or younger. My desire for multiple partner sex started when I was a very young boy who was curious about the anatomy of girls (we were all roughly the same age). Being concerned about getting into trouble for talking the girls into letting us look at them naked I would invite another boy along to join in with me to view the girl naked. Trouble loves company as the saying goes.
The first orgasm I had with a girl was as a teenager with a beautiful tomboy my age who gave me and my best friend blowjobs to completion, swallowing both our loads. I didn't realize at the time how lucky I was to have a swallower for my first blowjob and it was a threesome to boot.
My first multiple partner experience was with my brother and a roommate with a gorgeous blonde fun 18 year old new ...... who was divorcing. I still have the old school film pictures I scanned years later. (Funny, I had my ex-girlfriend's sister, who worked at a photo developer, develop the pictures for me. She always wanted me and i stupidly passed up a FMF with her and a friend because i was being faithful to her older sister (middle ......) who i was dating at the time and later cheated on me. She gave me a big sly smile when i picked up the pictures, asking me to say hello to my brother. I also passed up an opportunity with my girlfriend's oldest sister. They were all hot. One horny family of girls.)
I was given a copy of a swinger magazine at 25 where I came to realize that my desires to share a girlfriend/friend/wife was common and not as weird and unusual as I had assumed.
It has been a long unbelievably fantastic journey of many threesomes, foursomes, gangbangs, and later swapping with other couples, although no orgies (not my thing). With hopefully many more years to go. I'm 62 with a 30 year old fit girlfriend who isn't after money as many assume. She is with me because I intrigue her and how i treat her. Yes I'm bragging, but I also love older women too. 😃
I have been blessed.