It's not just you. This site is full of people who only prefer yaoi or yuri. There's even those who call everything not gay hetslop. -.-
I read everything and am not straight myself, but I ship Reirin with Shin-u. I have a best friend too and some people thought we were gay and honestly it was gross and irritating to assume.
It's a straight manga so usually I just read it expecting straight romance. I don't bring yuri or yaoi stuff into this genre nor the other way round. Even if it were yuri, I honestly dislike shipping Keigetsu with Reirin cause the things Keigetsu did need redemption, and I don't like her victimising, jealous mindset which isn't a good match with Reirin. She is cute as a tsun but other than that she needs work. And Reirin is someone who needs an equal and who can see through her tough front and recklessness to the point of self injury.

Why yuri?
Do you have no great friendship with woman? She's your bestie, your sister and your soulmate, and still have straight love story you can complain or laugh to each other? Just me?