Rido & Juri

Rido and Haruka both love Juri, they never got on because they were both rivals for her love. At first Juri was irritated by Haruka but after a while she returned Harukas affections due to the fact that he never gave up or fought back when she insulted him instead he just smiled. Rido was genuinly as fond of and in love with Juri as he was capable of and it is common for purebloods to marry eachother. So Rido probably thought that he would get Juri and Haruka would be the one to make a promising marriage. Only it didn't turn out that way and as soon as Haruka and Juri feel in love Rido eloped with Shiki's mother (who happens to be a striking beauty and aslo has hair like Juri's). Rido asked Yuki in Chapter 43 "Juri why am I not good enough?, Love you so much I feel like eating you whole" It's unclear what kind of relationship Juri and Rido shared but it is clear that Haruka had to protect Juri from Rido more than once. Rido seems to be obseesed with Juri and its clear that he lusts after her.