From the context I'd guess that he said that "coming just from your ass is something that only happens in porn"
Also, translator-san if you need help with editing or proofreading feel free to slide in my DMs and thank you for translating (ノ◕ヮ◕)ノ*.✧
From the context I'd guess that he said that "coming just from your ass is something that only happens in porn"