Let a Member Surprise Fuck your Wife Bare

I always had this fantasy, preferably with a known couple to do a surprise fuck, where both the Bull and the Wife are surprised by the Cuck, Wife is in the room with her ass up thinking the husband is going to fuck her when in reality the husband invited the bull to do it, But the Brown bull doesnt know and only when he is invited into the room secretly realises his gift, Any such videos or pics or stories?