Well, it doesn't hurt my stomach so to speak. But it feels heavy in my stomach after I've swallowed a good mouthful. My stomach definitely reacts to having cum inside of it, I believe it has a "WTF is this?" reaction. It feels weird in my tummy. Not a stabbing pain or an accute pain, but it feels more like I drank a short or two of sour milk. Hasn't dissuaded me from going back for more, so far.
If you could provide a picture of your tummy for the purpose of visualization we'd be most grateful hotwater