Sorry you do actually state he tells you this , perhaps ask him where and how he knows about it.
On reading your thread I have to ask ,could this be a learned behavior, has he seen anyone doing this ,it seems so unlikely a child of this age would think it up, any TV or PC he could have viewed , any adult magazines , not just in your house but in any house he visits, check out the avenues , and ask him more pertinent questions.How do you know he gets aroused when he reads a comic does he tell you this?
I wouldn't give it any attention whatsoever for awhile- just say- "let's get busy- it will be ok in a bit" - distracting him will help him train himself to be self disciplined in the future in this department----- my 2 cents- for whatever it's worth!
I don't know if it's normal- My two boys never told me about it nor did they cry about it- but that doesn't mean they didn't go through it-
Any men here remember?
Some people are just hypersensitive in all areas- sexual- emotional etc
I had a chiropractor do the neurological sensitivity test on me and my results showed I was hypersensitive to touch- stimulation-