My parents have a nice deck for sunning oneself out back behind the house. One warm day I slipped into my one piece floral-print swimsuit and went out on the back deck to sunbathe. Laying there on the lounge chair the warm sun felt so good, thinking of nothing in particular except how good the warm rays felt against my body. I breathed in and breathed out with a happy sigh, lungs filling with air then exhaling.
I didn't even realize what I was doing to myself until I felt my suit begin to pull tight against my body. The suit pinched at the shoulders and arms and legs. I just smiled, so happy, so relaxed, so glad for the sun on my body, that I continued to inhale and exhale. My breasts rose, and they really began to rise as they began to grow against the tight suit. As I breathed they blew up to the size of volleyballs, then large watermelons, then beachballs. The crotch of my suit grew tight, rubbing against my nether regions as the material pulled and rubbed, pulled and rubbed, against me as my gigantic breasts ballooned up bigger and bigger. I began to get aroused as the material rubbed against me down there. I started to breath in and out, faster and faster as the material tightened and rubbed/pulled, rubbed/pulled, rubbed/pulled snugly against me. I moaned, biting my lip then opening my mouth and gasping, inhaling, exhaling. My breasts rose and rose. Suddenly I cried out as I orgasmed with the tight swim suit rubbing against my stimulated genitalia. Sensations ebbing, I fell asleep in the chair warm and content with my breasts so big all sorts of tit flesh bulged from the straining suit.
Luckily, my body deflated by the time my folks returned--and found me roasted like a peanut asleep on the back deck under the sun!