Scorpios make loyal, loving, trustworthy friends (via YourTango). You can always count on them to have a deep conversation with you, whether you are trying to figure out how you feel about a recent date or are contemplating a new career or a major move. Their circles tend to be small, as they only feel certain people are truly worth investing their love, trust, and energy into. But once they've let you into their circle, you will be hard pressed to find a better friend.
They will always communicate with you honestly and directly, and they will always stick up for you, protect you, and be on your side, whether you are with them in person or not. Scorpios are generous with their time, their love, and their resources where it comes to those they love most, and they will always remember your birthday and other important events.
As with any other situation, the fastest way to get on your Scorpio friend's bad side is to lie or to be dishonest or disloyal. Talk about them behind their back or show that you aren't willing to be as invested in the friendship as they are, and you are likely to find yourself on the outside looking in pretty quickly.