I don't know what a milking scene should be like, but here's one I made quickly where if you hit the breasts (collision trigger), a milky fluid comes out.
This uses the default VAM model and you need this plugin:
⚠ PLEASE: If you like this plugin, consider liking and reviewing it for the community Read the description, read the ingame help if you have any trouble. I will not answer private messages asking questions about things that are actually...
hub.virtamate.com
The point is to show you a very basic scene, then you can build on it to make the kind of scenes you'd like.
Drop the file in /Saves/scene.