The red heart Snapchat emoji ❤️ is one of the best. It means that you and your friend have been BF or best friends for two weeks in a row. That is to say, you have interacted with each other more than any friend on your friend list for two weeks straight.
Should you like to be SBB or Super Best Friend with your best friend, you need to keep the red heart Snapchat emoji working for two months in a row. As soon as you have achieved it, the red heart Snapchat emoji will turn into pink hearts.
Take note that the red heart Snapchat ❤️ has nothing to do with a snap streak. A snap streak is when you have to send direct snaps to your friend (not chats) within the 24-hour time frame for over three days in a row. Rather, it is only when you send the most snaps to, and get the most snaps from with your friend.
Keep on doing it until you receive the pink hearts Snapchat emoji icon 💕.