Being a casual fan of the books, it occurred to me that in most cases, the couples I have seen in the Harry Potter stories all seem to come from the same house, with Harry and Cho Chang being an exception. This makes a certain amount of sense; the [mostly] friendly rivalry of Gryffindor, Ravenclaw, Hufflepuff, and Slytherin would to an extent preclude extended fraternization, and most time spent outside of study would be with housemates, both same sex and opposite. So it makes a bit of sense that most probable couple bounds or opportunities to pair up may occur literally "in-house". This would be elevated by the fact that, due to house members sharing similar traits and possible alignments, they would naturally have more in common with housemates [values, views, personality quirks, shared interests] which would be the best elements to build upon.
Close friendships aren't precluded by houses, though; Cedric Diggory was purportedly liked by most people, regardless of House affiliation, for instance. In The Cursed Child, concurrently, Albus and his cousin are in different houses, and grow steadily distant while he grows close to a Malfoy. So its not at all impossible that close friends can come from different houses, let alone crushes or possible paramours.
I was just wondering if I missed something, and if there were any in-canon examples of couples who came from different houses yet had successful relationships?
