What is the position of the step father and the biological father at the daughters wedding.? Specially under the Chupa.
There is no specific custom in this regard. It would depend on the daughter’s relationship with each one. Either way sensitivity should be shown to all parties, so no one should feel sidelined or slighted in any way. Many customs of the chuppah we do have are centered around making siman bracha. Certainly, avoiding any strife is the greatest siman bracha.