Yes if someone has the flu and you kiss that person and the person you kissed was still contagious with the flu then yes that flu virus can spread to your mouth and body through your mouth and you'll likely come down with the flu within a day or so.
If you know someone has the flu or a cold virus you should avoid kissing that person until they're no longer contagious with the flu or cold.
If you kiss someone with a cold or flu virus you'll be feeling miserable with the flu within a few days.