All web tests can be run in a single browser window using either by setting the thucydides.use.unique.browser system property or programmatically using runThucydides().inASingleSession() inside the junit runner.

package net.thucydides.showcase.jbehave;

import net.thucydides.jbehave.ThucydidesJUnitStories;

public class JBehaveTestCase extends ThucydidesJUnitStories {
    public JBehaveTestCase() {
      runThucydides().inASingleSession();
    }
}