When sitt on a chair you sit on your ischial tuberosities, your sit bones. The ischial pubic ramos connects the ischial tuberosities to the pubic bone. The internal portion of the clitoris and penis are attached to the ischial pubic ramos to give those organs structural support. When you straddle a narrow saddle, you don’t bear your weight on your ischial tuberosities like on a chair but on your ischial pubic ramos. The nerves and blood vessels running in Alcock’s canal are compressed against the bone. Straddling a traditional bike saddle x-rays show that all blood flow stops.
Sexual dysfunction is comprised of disorders of desire, arousal, orgasm and pain. Looking strictly at the biological aspect, arousal is affected by neural, vascular, endocrine and structural conditions. The bike seat affects both the neural and vascular conditions.