Who here has ever gotten a cold sore?

I recently drank after someone who gets them. The day after I drank after him he got one. It's been a week and my lips are itchy. He told me he feels bad because that's how he gave them to his ex girlfriend. That really concerns me. Which brings me to my first question is it actually possible I could of contracted the virus by drinking after him in the tingling stage? If so what would be my first sign?