Well, I don't typically masturbate in front of my partner unless he wants me to, as a turn on, or for foreplay.
He does in front of me on occasion, usually as a method of turning me on, sometimes not.
For me, it's not awkward if it is at his request, but sometimes can be if it isn't, simply because until my current relationship I've never masturbated in front of anyone before. He doesn't seem to care too much about himself doing it in front of me though.