Can you make it possible to have more mate options. If you kill someone's mate or makes them break up, so you can take them as your mate?
For example...If you wanted Harefur to be your mate:
1) Find his current mate, talk to them and figure their most fears or secrets. Use this as your advantage later.
(Make sure you have a great friendship Harefur or with another cat before continuing.)
2) Then makes sure she/he aren't in camp, and start spreading rumors about that cat or Deerlight. Click on Harefur or the other cats, they'll wikl tell you that they're worried with their relationship with them. Keep doing this a few more times.
3) Harefur or the some cat will tell you that they want to break up with their mate, and will ask you to get them a withered flower! Once you got it, report back to them, they'll will you to bring it to their mate. Their mate will become upset about and will try to talk it out. (Make it like a quest)
3.5) If they manage to work it out. Forge a letter about it with the withered rose. Which will ultimately break them up. Once you forge the letter, find the cat you want and place it in their spot.
(Wait until they come back...then Harefur or someone will be heartbroken about it)
4) Go to them a comfort them by bring prey, flowers or other items. Keeps doing this until they give your a pink tulip.
5) Have their children.
Or do it an easy way. Become a Medicine cat or wait until a gathering- Go to Fireclan and take the deathberries (Lunaerclaw will be gone). Click the river to hide them in a fish, and give it to the cat's partner. Boom murder, sleep or wait until the next gathering to announce their death. Then do step 4 and 1 (making sure you have a good relationship with them; by doing quest for them)