Del. Code tit. 10, § 3914

In any action by or against partners, the plaintiff may require the defendant or defendants to deny the allegation of partnership by affidavit filed with the answer, by the specific notation of the need for a denial by affidavit within the paragraph alleging partnership. Any defendant so answering shall deny the existence of the partnership as alleged, and stating to the best of the defendants’ knowledge and belief whether there is any partnership in relation to the subject matter of the action, and who are the partners therein. Where plaintiff has complied with this section, failure of any defendant to file an affidavit with the answer shall be deemed an admission of the partnership as alleged.