Staying in town lowers arousal, more if you upgrade the bar.How do you get rid of the hearts/horny level? Im always getting orgasmed stunned and they seem to last between runs.
One of the consumables in the provisions drops arousal by 20 each usage.
Some classes have ways to either remove arousal or transfer it to themselves.
Some curios during exploration can lower arousal.
Finally, when arousal hits maximum, an affliction is triggered. The afflictions Clearheaded and Denial immediately reset arousal (although Denial incurs a debuff on the character), while the others may force your characters into actions that raise satisfaction before arousal is fully reset. Note that afflicted characters can often masturbate to raise satisfaction without incurring a debuff (although that'll still skip their turn).