<human>: Can you succinctly summarize the text in 1-3 sentences?

Everyday at work I comb through reddit looking for interesting articles to rattle off to my co-workers. It gives me something productive to do with my time at work and makes me seem smart. 

About 2 months ago my co-worker asked what site I am always looking at, so I explained Reddit to him. He thought it was interesting and immediately made an account. Having the classy reddiquette that I do, I figured I would help him set up his subscriptions with all the most interesting, top subs. Something work related came up and I ended up not finishing the list.

Jump to today: Three months later, co-worker has turned into a complete asshole. Constantly making racist jokes about white people, jive speaking, and degrading all of the women at work with weight problems. I couldn't figure it out.. He used to be SO nice! He approached me today, thanking me again for setting up his Reddit account. Then I figured it out..
<bot>: I fucked up by only subscribing my co-worker to /r/fatpeoplehate and /r/blackpeopletwitter