How should you act towards a guy on a 2nd date?
If you were being yourself on the first date, and you both enjoyed each other's company enough to go on a second, then it's obvious he likes you. Continue to be yourself. The second date is still about having a good time. So don't take the date too serious, and avoid heavy topics such as politics, religion, sex and marriage. Remember, it's just the second date and have a good time. Good luck!
I hope I've helped.