If you're sent S on snapchat, they are sending streaks. To get streaks to work, send an S every dayback and forth. If they forget to send their S one day you are welcome to scream at them.
“S” probably stands for the word Spermatogenesisicalieperiocladicleesötáans. Well, actually, that isn’t a word, but I uploaded it to the Urban Dictionary and no one voted it to be in it yet god damn it, so do it NOOOOOWWWWWW.........