I don't think the problem is the arousal. At the moment I have set the arousal to 0.0015 or something like this.
When chatacters masturbate, the arousal level increases as it should do, but the orgasm never happens. The orgasm level reach 60-70% at the end of the animation. So, when the sims are done, the orgasm level is back to 0% but the arousal level remains the same. Sometimes the orgasm triggers with certain characters, but only during sex act with other sims.
I really don't want to manually trigger orgasm for each character that is turned in a sex crazed beast

Btw, thanks for the help