¶1A special provision of our statute is that “the husband and wife may in all criminal actions be witnesses for each other, but they shall in no case testify against each other except in a criminal prosecution for an offense committed by one against the other.” Code Crim. Proc. art. 735. And this rule rendering them incompetent to testify against each other' has also in this State been held to render them incompetent against a joint offender with either. Dill v. State, 1 Texas Ct. App. 278.
¶2As stated by Mr. Wharton in his work on Criminal Evidence, the rule is that “whenever a defendant is incompetent to testify for or against a co-defendant, then the husband or wife of such person is to the same extent incompetent. Thus, on a trial for conspiracy the wife of one of the defendants should not be allowed to testify against one of the others as to any act done by him in furtherance of the common design, if there be any evidence given connecting the husband with the defendants in the general conspiracy.” Whart. Crim. Evid. [8th ed.] 391.
¶3In the case before us it is not made to appear that Frank Williams, the husband of witness, was being prosecuted at all for this offense; the record here certainly *79does not show him to be a joint defendant in this case. If a prosecution had been commenced against him and afterwards nolle prossed, the wife would have been competent it seems (1 Texas Ct. App. 278), and whenever a co-defendant is admissible his wife would be admissible. Whart.’s Crim. Ev. § 391; Blackburn v. Comm. 12 Bush (Ky.), 481; Ray v. Comm. 12 Bush (Ky.), 397.
¶4But, even if it had been made to appear that the witness was incompetent on account of her relationship as wife to a joint or co-defendant, still in this instance the testimony was not objected to at the time by the defendant, and an objection to the inadmissibility of evidence cannot be availed of after verdict, when no objection was interposed at the time it was admitted. Objection to incompetent or inadmissible evidence should be made as soon as its illegality can be ascertained. Cole v. State, 40 Texas, 147; Harman v. State, 3 Texas Ct. App. 51.
¶5The main witness against defendant was one Ann Williams. On her examination it was developed that, subsequently to the date of the alleged offense, she, the witness, had had a difficulty with both her husband and this defendant, on account of which she, months after this offense was charged to have been committed, procured or endeavored to procure the arrest of her husband, and at the same time made complaint against defendant, upon which he was arrested for the crime preferred against him in this indictment. To show the extent of her bias and prejudice towards defendant, his counsel proposed to have the witness state the nature and cause of this difficulty, which, on objection by the prosecution, was excluded by the court. In this we are of opinion the court erred. Generally on cross-examination a witness may be asked any question which may have a tendency to affect his credit, and it is the right' of the defendant to show the animus and bias of a witness towards him, and its extent, if he can, Whart. Crim. Evid. (8th ed.)§ 376; Blunt *80v. State, 9 Texas Ct. App. 234. And as to his relations to the defendant, he may always be asked. Whart. Crim. Ev. § 477.
¶6For error in excluding or refusing to permit the introduction of this evidence, the judgment is reversed and the cause remanded.
¶7Reversed and remanded.