How likely is it to get herpes if I have an early coldsore and my partner kissed me lightly then gave me oral?

No risk for you. The only risk here is for your partner to catch oral herpes, if he was not previously infected with HSV1. People with HSV are immune (or at least highly resistant) to new infections with the type they already have. Therefore, your oral herpes (probably HSV1) will never be transmitted to your own genital area, either on your own fingers or hands or by your partner's mouth.
Increased risk. Herpes simplex from a cold sore is quite contagious. Kissing is a good way to pass the virus and infect your partner. If he then performs oral sex on you, he can transmit the virus to your genital area. 30% of genital herpes is due to HSV 1 commonly causing cold sores. You can also auto innoculate, if you touch your lips and then later go to the restroom and accidentally touch the genital area.