There's no guarantee that you will definitely get a cold sore if you kiss someone who has a cold sore.
But most times you will usually get a cold sore if you do kiss someone who has a cold sore.
My girlfriend years ago had a cold sore and I kissed her and yes I did eventually a few days later come down with a cold sore myself.
So I would avoid kissing someone who has a cold sore because the virus that causes cold sores is highly contagious to other people.
So it's best to wait until the persons cold sore is gone before you kiss them to avoid you getting a cold sore from the person.
No matter how much I love the person I would never kiss them again until their cold sore is gone and I would not want someone to kiss me when I have a cold sore.