What Causes Yellow Bumps On Lip After Oral Sex?

The guy i am dating told me he gets coldsores...which i automatically associate w/ herpes. I never saw an outbreak on him and we've been dating exclusively for almost 6 months..however last night he gave me oral sex and as we were falling asleep i could have sworn i saw a yellow-ish bump on the tip of his lip...IM FREAKING OUT...Does this mean im going to get genital herpes?