Why do guys refuse to give me a piggyback ride (brutally honest answers please)?

When guys are playing around with us ladies like teasing us or giving us piggy back rides, I'm isolated. Seriously. One of the things that I HATE about being a tall girl is that I can NEVER get piggy back rides! It's awful. I'm 5'10 tall, large-framed, 232lbs, and thick. I'm jealous of the petite and average height girls because they can get piggy back rides and get picked up. Even the tall, small framed slender girls can get picked up. I will NEVER be petite. They're tall but shorter than me. When I want a piggy back ride, guys either back away from me or say, "You're too BIG to get a piggy back ride. You might crush us!" I wanted this cute guy to give me a piggy back ride, but he's like 6' and he said he was like 167lbs and I'm WAY to heavy for him. He instead gave a piggy back ride to a shorter girl. Am I THAT heavy? Even guys taller than me won't give me a piggy back ride. ='(