It's never a good sign when the yaoi manga first sex scene is nonconsensual. Does the word "NO" not mean anything anymore? Well...the story gets kinda better after the first chapter sort of. Spoilers:
When the twins tried to sexually assault Sae they backed off after seeing how traumatized he was, and decided to stop messing with him. At least they acknowledged they were in the wrong and apologized, which is a far cry from most yaois that contain non-con so this gets a w from me.
Aisaretagari No Gemini