Aisaretagari No Gemini summary:

I want to be with them, but I don't want to be with them. Sae Hagiura, an ordinary college student who wants to live a normal life without being conspicuous, ends up helping two handsome twins, Shu and Yu, who are rumored to be in a fight in front of a brothel, and in return, they offer him sexual favors. Sae is strangely attracted to them, but their time together is becoming "normal," and Shu and Yu also begin to develop special feelings for Sae, who does not look at them with a different set of glasses...