Under the... Tradition I was raised in, One was married to the one you had sex with, One Flesh meant One Flesh. If you have sex with 4 people, you are bound forever to each one of them, ‘til death do us part. The ceremony, Church Vows, etc. were all window dressing on a central indelible fact.
There’s also the issue of imprinting. One imprints on their first sex partner, the second (especially if it is a short while later) blurs the focus, the third further blurs, by the tenth or so, there is no focus. No subsequent partner can ever fit the established template, there will always be a sense of them not being quite right.
Indians seem to have pretty good arranged marriages, besides the factors of parents who arrange the marriage having more experience in judging people, besides the parents not being under the influence of raging hormones, besides the parents selecting from families in similar circumstance, with similar values, the first sexual encounter is after marriage, and by the time they’ve worked through the traditional wedding present of the Kama Sutra, they are pretty thoroughly imprinted on each other!