Yes if someone has the flu and you kiss that person the flu virus can be spread to you through your mouth when kissing that person.
Having the flu you'll be very contagious for at least 4 days after the flu begins so you should kissing or making contact with the person if possible.
Just being around other people with the flu can cause you to catch the flu virus so avoid people with the flu if possible and stay home from work or school when you have the flu until it's gone or until you're no longer contagious.