I need help! what am I doing wrong?

So guys I'm a noob and I'm stuck I just need to know where I've gone wrong Here is the code (ignore the friends_name that's fine)

char friend_sex [1];

cout << "Please enter m if your friend is male or f if your friend is female\n";

cin >> friend_sex; 
    if (friend_sex == "m") cout << "If you see " << friends_name << "! please ask him to call me\n";

    if (friend_sex == "f") cout << "If you see " << friends_name << "! please ask her to call me\n";

When I run it it says "Run-Time check failure #2 - stack around the variable 'friend_sex' was corrupted."

Any help would be appreciated :)