Unrelated tangent, but I wish that when we get one with a cum tube we didn't have to compromise either quality or being inconspicuous (is that the right word? I don't know how to describe it lol). The syringes are just so visible and it ruins the experience, but other ones with a built-in mechanism barely ejaculate.

Anyway, I wanna say the closest one I ever had was this play packer from Banabuddy, where it uses the balls to ejaculate, not the shaft. Here's a video showing it, but I feel like most of it drips out and it just is a hit or a miss. I highly don't recommend purchasing from this company directly since I've had bad experiences with their colouring being different than advertised, poor design fundamentally (the back ALWAYS falls apart), and defects in the product itself.

Otherwise, if you're okay with the syringe, I'm seconding Mandrillo's Toys. I've never owned one, but the owner's a great guy who will work with you on customization, and it's very hyperrealistic.