Well, as I mentioned in your other posed question, http://www.italki.com/answers/question/67572.htm I thought that you have referred to some information that I provided when I previously answered to another very similar question as given in, http://www.italki.com/answers/question/56562.htm but it looks like that you have not referred to it. My personal suggestion is that, in general, the answer is "no". A younger boy/man (male gender) should address to an elder boy/man (male gender) as "형 (hyeong)", or as an honorific form, "형님 (hyeong-nim)". One of the exceptions might be, when a younger boy/man wants to make jokes to an elder one by laughing him at a matter that he acts like a lady, then perhaps he might use "오빠 (o-bba, or o-ppa)" in such occasion. However, I would not encourage such joke-making unless they are very close friends. Good day. / 좋은 일일 을.