Olivia Bentley and her boyfriend Tristan Phipps have been photographed having a "heated" argument in a park.The Made In Chelsea star, who recently wowed fans with her incredible short hair transformation, was seen sitting on the grass at Parson's Green, dressed in a light blue jumper as she waved her hands to the side.Tristan, 24, could be seen wearing a black T-shirt with matching shorts as he sat on the grass near her.