Looking for a hentai manga

Im searching for a hentai i saw years ago, where a guy makes his girlfriend or something have sex with multiple other guys in order to collect energy? (im not sure). Only thing i remember is that in the end he says something along the lines of "Soon i will reach my objective" and she says "I will do everything for you". I tried searching multiples combinations of tags and coudn't find, so if anyone know something would help a lot thanks.