We've all heard two friends execuse their not dating each other with, "He's like a brother to me." or "She's like a sister to me." I've always been suspicious of this execuse. I feel that's code for we're desperately in love with each other and we're fearful of those feelings. Or one party is in love with the other and to save the friendship we replace, "The idea of me having sex with you makes me want to vomit." to "You're like a brother to me."
I have had many male friends. I have never loved any of them like a brother. However, I have had loved some of them like a cousin. The thought of sleeping with them never really occurred to me, but if my situation got desperate I'm sure my parents would try to arrange for me to marry one of them.