I hate to be that guy, but...

A phrase people can add before saying something nitpicky, like correcting you on some inconsequential fact.

Often secretly means, "I love to be that guy", since the kind of people who say it get a little thrill from correcting others and being pedantic.

I hate this guy/(and or you)
In the world of not texting back this is a means of a romantic gesture, using the term " I hate you" actually is a way of expressing "I like/love you". As was previously mentioned, girls with trust issues are too scared to love, so they show said emotion through acts of hate.