it depends on the content of the session and how much I allow her to see. Sometimes we wrap up, other times I'm left sitting in the car in the parking lot wishing I had more time. Days like that I will try to journal on my phone for a bit. I have a 30-45 minute ride home, so I sometimes blast music that speaks to my emotion of the moment. If I really feel out of sorts and don't want to go home right away (I have no alone time at home most of the time), I will grab coffee or lunch or go window shopping first. Sometimes I take the long way home (back roads as opposed to the highway) which doubles my travel time but also gives me a chance to re-group.
Sometimes my wife comes along for the ride and I process with her if I need to/want to. Most of the time though, I make sure to put on a happy face before she opens her office door. There are usually people in the hallways or in the waiting room and I don't like anyone seeing me cry.