Mates

Mate is the Clan word for a partnership between a tom and a she-cat who love each other and plan to spend their life together, and possibly have kits.

Taking a Mate
Two cats are usually considered mates after spending some time together, and after some kind of confession of love. Clan cats usually take a mate from the same Clan, although there were examples of pairings from different Clans. Similarly, loners, rogues and kittypets generally take other loners, rogues and kittypets as mates.

Breaking Up
In the Warriors universe, breaking up is fairly rare. Some examples of mates who broke up:
 * Daisy and Spiderleg
 * Squirrelflight and Ashfur
 * Squirrelflight and Brambleclaw
 * Leafpool and Crowfeather

Reasons
Mates break up mainly for the following reasons:
 * They decide they are not suited for each other
 * A cat does not love their mate anymore (Daisy and Spiderleg)
 * Ending a relationship of forbidden love by mutual agreement, recognizing that loyalty to their Clan is more important than their love (Leafpool and Crowfeather)
 * Disagreements, mistrust (Squirrelflight and Brambleclaw in Starlight)
 * Disappointment in their mate's actions or behavior (Squirrelflight and Brambleclaw in Sunrise)
 * One of the cats leave the Clan (Goldenflower and Tigerstar)
 * One of the cats die (Graystripe takes Millie as a mate after the death of Silverstream)

In some cases, mates will get back together some time after breaking up.

Restrictions

 * Taking a cat from another Clan (or a non-Clan cat) as mate is implicitly forbidden by the first rule of The Warrior Code, as such pairings are considered a sign of disloyalty. Kits born from such relations are named half-Clan, and usually mistrusted.
 * Medicine cats, either male or female, are not allowed to take mates, in order to not be distracted from their mission and work.
 * Apprentices do not take mates because they are young, though they do fall in love.

ThunderClan

 * Adderfang and Swiftbreeze
 * Berrynose and Poppyfrost
 * Birchfall and Whitewing
 * Brackenfur and Sorreltail
 * Brambleclaw and Squirrelflight
 * Cloudtail and Brightheart
 * Dustpelt and Ferncloud
 * Firestar and Sandstorm
 * Fuzzypelt and Robinwing
 * Graystripe and Millie
 * Halftail and One-eye
 * Pinestar and Leopardfoot
 * Smallear and Speckletail
 * Stormtail and Moonflower
 * Spiderleg and Daisy
 * Thistleclaw and Snowfur
 * Tigerstar and Goldenflower
 * Whitestorm and Willowpelt
 * Windflight and Poppydawn

WindClan

 * Crowfeather and Nightcloud
 * Windstar and Gorsefur

RiverClan

 * Whiteclaw and Leopardstar

ShadowClan

 * Raggedstar and Yellowfang
 * Rowanclaw and Tawnypelt

Other

 * Cloudstar and Birdflight
 * Crowfeather and Leafpool
 * Graystripe and Silverstream
 * Oakheart and Bluestar
 * Ryewhisker and Cloudberry
 * Smoky and Daisy
 * Smoky and Floss
 * Stone Song and Broken Shadow
 * Stormfur and Brook
 * Tigerstar and Sasha