>>76739601
they are caused by your muscles growing too quickly, like you said. Some people get them some don't it depends on the speed of growth, genetics, etc, specifically the amount of collagen in your skin. The amount of collagen in your skin is like most things in a body regulated by a bunch of factors but there are 2 you should focus on, the amount of vitamin c and the amount of protein, the protein you seem to have covered so now just make sure you also eat your veggies.
all that might reduce the chance of getting more.
but honestly if you can you shouldnt worry about them, they are just a sign that you got stronger, gj