First time I've done one of these challenges!

Decide to do it in C#

` class Program { void PrintRyhme(string firstLetter, string name, string nameLess) {
Console.Write(name + ", " + name+ " "); if(firstLetter.Equals("B")) { Console.Write("Bo-"); } else { Console.Write("bo B"); } Console.WriteLine(nameLess + ",");

        Console.Write("Bonana fanna ");
        if (firstLetter.Equals("F")) { Console.Write("Fo-"); }
        else { Console.Write("fo F"); }
        Console.WriteLine(nameLess + ",");

        Console.Write("Fee fy ");
        if (firstLetter.Equals("M")) { Console.Write("Mo-"); }
        else { Console.Write("mo M"); }
        Console.WriteLine(nameLess + ",");

        Console.WriteLine(name + "!");
    }

    int IsException(string letter, string[] args)
    {
        foreach (string s in args)
        {
            if (letter.Equals(s))
            {
                return 1;
            }
        }

        return 0;
    }

    static int Main(string[] args)
    {
        if(args.Length != 0 && args.Length > 1)
        {
            Console.WriteLine("Please enter only one name");
            return 1;
        }

        int exp = 0;
        string[] exceptions = { "A", "E", "I", "O", "U" };

        Program test = new Program();            

        string name = args[0].Replace("!", "");

        string firstLetter = name.Substring(0, 1);

        exp = test.IsException(firstLetter, exceptions);
        if (exp == 1)
        {
            test.PrintRyhme(firstLetter, name, name.ToLower());
        }
        else
        {
            string nameLess = name.Remove(0,1);
            test.PrintRyhme(firstLetter, name, nameLess);
        }

        return 0;
     }
}`

output: