In an isolated colony of a few hundred people, a curse has ensured that no-one is attracted to anyone who likes them. Additionally everyone does like somebody else - a different person in every case.
This means that everyone suffers from unrequited love and they have a
stalker unwanted admirer.
The curse is not removable.
In order for the colony to continue, people must procreate.
What is an effective solution for this problem of procreation?
Assume that people refuse point-blank to have sex with their
stalker unwanted admirer. No violence or coercion (i.e. rape) is allowed in this colony on pain of life-imprisonment. Of course the stalker's stalker admirer will still love them despite their heinous crime.
Only mature mentally sound adults are affected by this curse in either direction.
If there is an odd number of people at any given time, then one person is fated to fall in love with themselves and at the same time be disgusted by that fact. EDIT It has been pointed out by @Franklin Pezzuti Dyer, in their answer, and @Guy G in a comment, that requirement 2 changes the maths. I have decided to relax this requirement to avoid invalidating anyone's existing answer. You may now assume that (2) is true or false according to your own preference.
I originally intended the curse-afflicted people to be so possessed that they could not resist following their crush around. This was supposed to be part of the curse and why I initially referred to them as stalkers. Obviously I did not make this clear and people answered on the basis that they needn't be so obsessed. For that reason I have relented and edited to use the term unwanted admirer. In the event I am happy with the answer I eventually accepted. Thanks to all.