Immediately, as in as soon as alcoholic induced ecstasy is reached, you’d better lay down the law. Don’t even bother to get up and rinse off. Tell her as firm as possible that nothing, absolutely nothing will come from what just happened. Don’t exchange numbers with her. Don’t give her your social media contact. Nothing. Use the alcohol as an excuse for what went down. Use the ole “we work together” excuse. Tell her anything she needs to hear to keep from damaging her ego… at all costs. One false move and your business will be plastered on the communal bulletin board in the lunch room. Whatever it takes to imprint on her impressionable intoxicated mind that nothing else will happen, do it.