Is that a male human sexual organ engorged with blood due to physiological stimuli in your pants or are you just happy to see me?

[Pure Guava 325]

The cerebral cortex can initiate erection in the absence of direct mechanical stimulation (in response to visual, auditory, olfactory, imagined, or tactile stimuli) acting through erectile centers in the lumbar and sacral regions of the spinal cord. The cortex may suppress erection, even in the presence of mechanical stimulation, as may other psychological, emotional, and environmental factors.