Dekiai Moratorium: Outotsu na Futari ga Pair ni Naru made

Momo's engagement was broken off by her cheating ex-fiancé. Though she doesn't need the rings anymore, Momo couldn't give up the matching rings she commissioned from the famous designer Makino...That night, Momo runs into Makino, and they spend the night drinking together; Momo ends up telling him everything. The next day, Momo wakes up to a naked Makino?! On top of that, he says, "I handed in our marriage application, so now we're husband and wife..." Despite being ditched at the altar, she somehow found herself a handsome husband?!

(Source: Bunkasha, translated)