It’s not easy to completely disappear on someone forever.
It doesn’t seem like it at all right now perhaps, but if your Borderline ex has discarded you, they have done you a favor.
These people will have dates on a regular basis, and they may or may not be having sexual relations.
This period of courtship is sometimes seen as a precursor to engagement.
Accordingly, there was little need for a temporary trial period such as dating before a permanent community-recognized union was formed between a man and a woman.
While pair-bonds of varying forms were recognized by most societies as acceptable social arrangements, marriage was reserved for heterosexual pairings and had a transactional nature, where wives were in many cases a form of property being exchanged between father and husband, and who would have to serve the function of reproduction.
However, one particularity of the human species is that pair bonds are often formed without necessarily having the intention of reproduction.