an Hourglass. As soon as you recognized the symbols the ride started up and the tea cups started to start up. You were on the edge to avoid potentially crushing the little girls and you were making the tea cup spin so the girls would slam into you instead of you slamming into them. Then you started to spin the cups faster and faster then you stopped spinning when the girls started to get a little scared, but the tea cup didn't stop accelerating. After a few seconds Shauna said "Slow Down! Make It Slower!"
You responded by saying "It's Not Me! I'm Not Even Touching It!" and the girls started screaming a bit as your tried to slow down the ride. Your eyes stopped being able to see properly due to the speed as you tried to stop the ride. As the ride continued the girl's screams got a little deeper but your grip on the wheel also strengthened. Then the ride stopped and the girls slammed into you. You looked down and saw the girls had grown and gotten bigger. They looked like the Senior or older Juniors at your high school then noted their clothes did not grow with them their dresses managed to cover their breasts with mixed results. Shauna's breasts were covered alright, Sara's dress covered most of her upper body being the least endowed, and Sandra's dress barely draped her nipples with her massive chest. You guessed their stockings may have shredded and their panties may have remained in tact but you didn't want to check.
Shauna who opened her eyes saw you and said "Sam you grew up!" then covered her mouth and looked at her body then the bodies of her friends she was underneath and then said "We all grew up!.." then her face got red as she realized how scantily clothed they were. A little concerned once the girls got off of you you looked at your own clothes and your baggy shorts definitely were a little tight especially in the crotch area which you were a little happy about, and your T-shirt was skin tight as well but your clothes were holding out pretty well.
Seeing as how you were clothed you got out of the T-cups and said "I'll go look for some clothes or a changing room. I'll be right back!" but when you returned.