the vampire diaries actor and his twilight actress fiancée tied the knot on sunday in the santa monica mountains .
nikki , 26 - who was previously married to singer-songwriter paul mcdonald - wore a stunning white lace long-sleeved custom gown by claire pettibone , while ian , 36 , donned a white suit and shirt .
he was seen carefully picking up the train of her dress to protect it from the floor as the couple held hands - at one point .