No! It can happen. But if you are a true nudist, this normally does not happen.
Sorry if I'm COMPLETELY wrong but I think you mean hentai
Your question suggests to me that you might be thinking there is something wrong with you when you get an erection over your sister. There is nothing wrong with you. Your body is filled with testosterone right now and anything that moves, looks, smells, and sounds like a female is likely to give you an erection. It's not you - it's your body doing what it's supposed to do. You are NORMAL. You see her as your sister; your body sees her as a female, and to a boy at your age, female means, erection. That's just the way it is. So stop worrying about it. In fact, the next time you get an erection "Over your sister", say to yourself, "Excellent - I'm normal. And I understand why my body is doing this. I love my sister, but not in that way."
It's never wrong to have an erection. Embarrassing or awkward maybe but an 8 year old can have one.
Dee Caffari
no
I think you should get that checked out.
Then something has obviously gone wrong with the neutering.
take it to the vet.
No. It just mean you are not easy to get horny.
Nothing, an erection at age 13 is completely normal. Like the person before me it is normal. You are just going through puberty.
No you should not you creep annd if you do get some new mates because that is wrong a disrespectful!!
Totally normal, I pee with a boner all the time.