Most Helpful Guy
Perhaps he is of the opinion that by disclaiming some of his kids, his financial obligation in support of them will be minimized. In brief, he is attempting to reduce his child support payments. But, as the anonymous user implied, DNA testing can expose the truth.
With regard to him being aroused by your daughter and his actions with an animal, it's definitely a cause for concern. Did you not report your suspicions to the authorities when it occurred? Did you allow him to continue to interact with you daughter? These are questions you may be asked by the court if you bring forth such allegations against him.
And if your answers are not satisfactory to the judge, the allegations may work against you as well. In which case, your kids could be placed in the custody of the courts or foster care.
Nonetheless, stick to the facts during the court process. Whatever they may be or no matter how awful they may seem. Therefor, there is no need to character assassinate your ex or/and over do it. His lies, excuses, and lack of stability will reveal his poor character in court more than you will.
Most Helpful Girl
Because he is a dumb ass