Ok this is to help anyone with mates!
-App mates-
Breezepaw: If you are female and have gotten at least 20 redemption in the hunting grounds then talk to Breezepaw a lot then she will ask if you wanted to hang out at the beach like Duskfall and Cottenwillow. (NOTE: This only works if your female AND an app)
Dustpaw (kinda): If you're are male and an app you have to let Dustpaw win tic-tac-toe three times he will blush knowing that you're letting him win on purpose. If you ask him if he likes you then he will say yes but he won't be mates with you. But he does say that if you still like him then he will be your mate as a warrior.
-Warrior mates-
Breezesong: If you are either female or non-bio then you can ask to be mates as she will say yes. (NOTE: when she becomes the leader of Fireclan then you two can adopt kits together)
Nightwhisper: If you are any gender then ask her to be mates she will be shocked and say yes. (NOTE: you can't have kits with her if you are female)
Cottenwillow: If you are male or Non-Bio then win guess the number three times if you say no to playing a fourth time she will ask if you wanted to go to the beach. Then when she kisses you after splashing water on her a couple of times you can ask her to be mates she will say yes.
Fallenfeather: If you are male or non-bio talk to her a lot then you will get the option to ask to be mates. (NOTE: it's a random chance for a yes so you might have to ask her a LOT)
Duskfall: If you are female or non-bio and a warrior if you say no to battle trining with him he will ask if you want to hang out by the beach. then like Cottenwillow splash water on him a couple of times then he will kiss you. Then you can ask him to be mates and he will say yes (NOTE: He will break up with you if you ask to be mates with Dustfeather in front of him. You can avoide this by having kits with Duskfall then asking Dustfeather to be mates)
Dustfeather: If you are female or non-bio or you are male and did the task of letting him win tic-tac-toe as an app and you are a warrior you get to ask him to be mates. (NOTE: Like Fallenfeeather you have to ask him a lot to be your mate but if you are male and did the steps as an app then you can ask once and he will be your mate! Please note that if you are male and asked him you can't have kits... also you HAVE to do the steps as an app other wise you can't ask him...) (NOTE 2: If you are mates with him as a female or non-bio and ask Duskfall to hang out at the beach he will ask if it's just a "friendly" walk. This is where you can have the choice of breaking up with him. If you say yes then you two break up. If you say no then you can be mates with both Dustfeather and Duskfall. Or you can have kits with him to avoid the whole thing)
And that is all the mates explained! I hope this helps!