Note: In this question, I'm asking about animals that have a penis that functions very similarly to humans. I've read some animals have dramatically different methods of copulation and physiologies, so for simplicity I'm only asking about males with reproductive systems very similar to mammals, birds, etc. However, if you feel a certain species deserves special note, please tell me about it.
Are there any animals that can ejaculate at will, while awake, without any form of physical contact with the sexual organs?
I read that a Muscovy drake everts his penis in about a third of a second and the accompanying video shows ejaculation once eversion is complete. This is so fast that I wondered how the male could aim accurately into a female's cloaca. I began wondering if the process was voluntary or involuntary, since a voluntary process seemingly would allow greater accuracy.
So, this led me to wonder are any animals capable of ejaculating at will without any form of physical stimulation to the penis or body?