I though the first couple of chapters were worse compared to the new ones but I guess it can be different for everyone. And the penis model is changed with this new chapter and the older chapters will get that change in time.I can't really go into those details, as I haven't really kept up with where exactly I was in the story, but if I had to guess, I'd say around chapter 3-4 is when the Grammar degraded too much for me to enjoy the story...
That being said, the first couple of chapters where absolutely AMAZING and it saddens me that the grammar is what ended up killing it for me...
The only other complaint I could really think about would be the "tube" penis that MC has... Although stuff like that is just nit-picking and overall not something that really bothers me.
But again, Keep up the good work, and maybe sometime down the future you could hire a professional proof-reader to iron out the grammar issues?
I'll probably pop my head in in an update or 2! c: