Cross examination of defendant with conflict of interst

I am plaintiff in a civil suit regarding partition of ancestral property. There are 18 (eighteen) defendants in the suit. Def. No 18 is son of Def. No 1 and both of them have same interest and are colluding with each other. Def No 1 &18 have conflict of interest with Def No 10 who is DW 1 in this case. After the cross examination by the plaintiff of Def No 10 (DW 1), advocate of Def No 18 found some conflict of interest, requested for cross examination of Def No 10 (DW 1), which was allowed and he finished his cross examination. Now Advocate for Def No. 1 has requested to allow him to cross examine Def No 10 (DW 1) for the same conflict of interest. Now my question is:
Can two colluding defendants (Def No 1 and Def No 18) cross examine Def No 10 (DW 1) separately for same conflict of interest?