Oh yes, that does happen. My younger bro suddenly became attracted to me "like real bad" when he started puberty. I used to flirt, flash, and tease him as a form of torture because I thought it was so funny. Then I began getting really turned on by our weird relationship, too.
Pretty soon, we were doing all sorts of naked stuff with each other (oral, mutual masturbation, wet humping, deep kissing, and finally full-on penetration with zero protection). It was great. Our fun lasted a long time, and we still hook-up a few times per year when we can schedule a secret date (nobody suspects anything, of course; who would think a bro & sis could be lovers?!?!?!).
During a recent reunion, I found out that several of my friends had f*cked their own bros all throughout high school. Sibling taboo love is definitely the best!!! No drama, no jealousy, pure naughty pleasures, living together "under-the-radar-in-the-same-house", nightly hook-ups, showering together... yup!!!