How can I clear the buffer between Console.ReadLin e() inputs (do-while input)

[Themantimes8]

I am making a game that requires input to be taken until the user inputs "exit" to the console. That part is taken care of with a simple do-while loop where i ask for user input:

do
{
    string input = Console.ReadLine();
    game.getInput(input); //input validation (disregard)
}
while (Console.ReadLine().ToLower() != "exit");
 

Now here is the problem: When I run the Console application, I input a string such as "walk north" and the program responds accordingly. The second time I input anything, the program does not respond and I must input a value again for the value to be read in. Every other input is disregarded as no value being input. I suspect the buffer isn't being cleared between inputs, but I have never dealt with that in C#. Here is an example of what happens:

(Console Starts)
Console has started! //introduction to program
>hello     //what the user inputs: prints value on next line
hello      
>hello2     //second input (supposed to print to next line)
>hello2     //third input is taken and printed normally
hello2
>hello3     //fourth input (supposed to print to next line)
 

All even numbered inputs do nothing.

It seems that every other input is completely disregarded and tossed out even though the user has input something new. Any idea how to clear the buffer between or set up the loop in a better way to accept user input without this "every other input doesn't work" business?

EDIT: In case it matters, the game.getInput() function returns in all cases.

Thanks,

Themantimes8

FINAL EDIT:
After reviewing Rabbit's tip, I reconstructed the loop to look like this:

do
            {
                string input = Console.ReadLine();
                if (String.IsNullOrEmpty(input))
                {
                    Console.Out.WriteLine("Invalid Input");
                }
                else if (input == "exit")
                {
                    exit = true;
                }
                else
                {
                    game.getInput(input);
                }
            }
            while (!exit);

This seems to have solved all problems I had before. Thanks Rabbit!

[Rabbit]

That's because you're reading 2 lines for each loop iteration. You're reading one line at 3 and one line at 6.

[Themantimes8]

Ohh. Thanks a lot man! I didn't even realize that it would have any affect on the line. Great Job! Would give best answer, but there was no recommendation on how to fix. Thanks anyways!

EDIT: Using Rabbit's tip I could find a way to fix (was tricky though) so might as well give best answer honestly. I guess not all best tips have to explicitly explain the solution, but have some hint that allows the user to come up with their own solution.