From Renta:

"I can't get it up...? What's wrong with my body...!!?" On the day after his birthday, naughty high-schooler Yuki finds out an astonishing truth: he's not actually related to his older twin brothers, Rai and Mei. Has the shock of this discovery made Yuki impotent!? Yuki's feeling down and is worried about his erectile dysfunction, but the silly, macho Rai and smart, caring Mei offer to fix his problem by bathing with him. The three of them in the bath together reminds Yuki of when they were kids, but suddenly, Rai's hand reaches for Yuki's crotch! What's worse is, Yuki, who couldn't get an erection from looking at girls, gets rock-hard from his brothers' foreplay!

"ガテンとインテリ、双子の兄貴と俺のスイートラブ・ライフ⁈" (Gaten to Interi, Futago no Aniki to Ore no Sweet Love Life?!/The Brawn and the Brain -My Sweet Love Life with Twin Brothers!-) is the title of the series when it was released per chapter in 2016.
"双子の兄のどちらか選べと言われても" (Futago no Ani no Dochira ka Erabe to Iwarete mo) is the title of the series when it was re-released as a tankoubon in 2017, which contained the previously released chapters and an extra chapter called "その気になれば俺だって" (Sono Ki ni Nareba Ore datte).