I live with my older sister and her husband and my sister's kids. and for the first month I noticed how me and my brother in law Jerry had chemistry. We talk a lot, were both potheads and we love to chill and smoke. Anyways, sometimes I catch him looking at me. And he is also an alcoholic and so is my sister. So they drink often, pretty much everyday. And when he gets drunk it seems like he gets braver. He laughs more with me, or flirts, or he will touch me. Just like on my shoulder, or on my thigh if we were sitting down.
It didn't exactly scream brother and sister in law relationship. I thought that was just how we were, we were just close.
