A line used by someone to make a quick getaway from a stale and awkward moment caused by this particular person. It is a voluntary assertion, to express the person's desire to leave the current location in which they may have just touched on a derogatory subject and it hasn't gone down well.
Miles: Hey David, nice of you to join me and my sophisticated upper class friends at this somewhat formal gathering here; what've you been doing this week then?
David: Well y'know... the usual; rapin' some peeps -
- I'll get my coat.