Why were they getting married at all?

Why were Orpheu and Mira getting married at all? He was actively pointing out the attractiveness of other girls right in front of her before they went to get the marriage license. He seemed like he wasnt even interested in getting married at all. She had to force him to buy her a ring and had to front her own money for it. He was flirting with other girls just a couple hours after getting the license. This just seems like the basis for a horrible marriage to me.