<human>: Can you give me the gist of the text in a nutshell?

So, I'm American [22 F] but live in France.  Moved here in September.  Back in maybe October, November, I made friends with a French guy, we'll call him C.  I could tell that when we first met, he clearly had a thing for me--drunkenly tried to make out with me a few times, that sort of thing.  On those few times, I pushed him away and told him "stahp i don't like you that way," and the next day I'd get a facebook message apologizing for acting like an ass.  

So problem enters here.  I'm also friends with a couple of his friends, plus his brother, who we'll call R.  R is super cute, super nice, and I really like him, and think I sort of LIKE like him, to use some middle school language.  So tonight, we were all at a club, and me and R were dancing, and started making out.  Continued for a couple songs, then we all decided to leave.  

C seemed sort of moody and annoyed, and I figured I knew why, my suspicions being confirmed when I later got a text saying something in francophone English along the lines of "I feel so jealous, I kind of got mad seeing you with my brother".  So.

Here are my feelings:  I feel bad that C is hurt because of me, but I also feel like I like R, his brother.  And I don't feel like I should be prevented from pursuing something with R just because C (to whom I owe no obligation) wouldn't like it.  But I also don't want to ruin my relationship with C, because I value his friendship, but I know that that is somewhat one-sided (i.e. he is looking for something that I cannot give him).  

So what should I do?  Is it entirely selfish of me to pursue R, knowing that my friend C is going to hurt from it, or should I not pursue R in order to not hurt C?

Please advise.  I don't know how to handle this situation.
<bot>: Friends with a guy who likes me.  I don't like him, but I DO like his brother, but don't want to hurt my friend by going out with his brother.