id say go on another date with each and make a decision after that, you are after all, only friends at this stage

You're dating matey. They'll both be adult enough to know they're not your only one. Most women know how men work in this respect (if they're honest), and besides, a little friendly competition never hurt anyone.

If you're confronted about it; be honest. Don't try and hide the fact. And don't try to dress it up either. Remember you're dating, you're not at the relationship stage yet. Its still open season. If either one are expecting you to be monogamous at this stage can you imagine how possessive they're going to get once you get serious?