my parakeet is male, his cere is blue and smooth, and every now and then i'll see that his vent looks swollen, lets just say i can see it, most of the time i never could but now i can but it doesnt stay swollen for long, it usually go's back to normal, today he was eating millet spray when it got swollen but it went back to normal about 3 minutes later, so whats wrong with him? is he sexually excited? hes in the same cage has a female he loves a lot