How to limit user input in C++ for strings & characters?

I'm trying to create a small restaurant program in which I'll be practicing everything I learned in C++ so far. However I jumped into a small issue. At the beginning of the program, I prompt the user whether they want to enter the program, or leave it by choosing Y or N. If the input is anything other than that the program will tell the user is invalid.

The issue is lets say the user input one invalid character a. The invalid output will be displayed normally and everything seems perfect. But if the user inputs two characters, or more, the invalid output case will be printed as many as the characters input by the user. Sample below:

Output image

#include <iostream>

int main()
{
    char ContinueAnswer;
    std::string Employee {"Lara"};
    std::cout << "\n\t\t\t---------------------------------------"
              << "\n\t\t\t|                                     |"    
              << "\n\t\t\t|            Welcome to OP            |"
              << "\n\t\t\t|Home to the best fast food in Orlando|"
              << "\n\t\t\t|                                     |"
              << "\n\t\t\t--------------------------------------|" << std::endl;

do
{
    std::cout << "\n\t\t\t    Would you like to enter? (Y/N)"
              << "\n\t\t\t                  "; std::cin >> ContinueAnswer;
    if(ContinueAnswer == 'y' || ContinueAnswer == 'Y')
    {
        system("cls");
        std::cout << "\n\t\t\t              My name is " << Employee << "."
                  << "\n\t\t\tI will assist you as we go through the menu." << std::endl;
    }
    else if(ContinueAnswer == 'n' || ContinueAnswer == 'N')
    {
        std::cout << "\t\t\t\tGoodbye and come again!" << std::endl;
        return 0;
    }
    else
        std::cout << "\n\t\t\t\t  Invalid Response" << std::endl;
}
while(ContinueAnswer != 'y' && ContinueAnswer != 'Y')

Thank you for taking time to read and for anyone who answers :)