Should i tell my parents what my brother is doing?

My brother is 22 and will be 23 next month. He recently just moved back in with us because he does dumb stuff and he got involved with cops. I have snitched on him my whole life but now that im 15 i try not to, or when i do i tell my parents that they found out themselves and i never told them. But i noticed that when i search things the first thing that pops up in the history is porn my brother has watched. I have also caught him watching it a couple times but i never told. Its getting really out of hand now because if you leave my pc on for like and hour or two it crashes. And this is MY laptop i dont want him ruining it because of all the viruses. Should i tell my parents