I get very attached to partners but i want the relationship to be open
I really want someone that is my main person; who I am with for decades, I want to be very close to them emotionally and enjoy sex with them. I also want to have many other relationships where I am close emotionally and sexually but less significantly, and have one night stands, WHILE I am in this long term relationship with my "primary partner". I am 21 but I have felt this way for a while. So, is it normal to want a very long term "open relationship"?
Note: Not sure if I'd bother getting married? Would also like to hear IN THE COMMENTS, if you think it would be normal for me to want an open marriage with the same attributes described above.