I must admit I never cum in my mouth. Having said that, I find when I'm wanking on my back that as I get close to cumming I'm looking forward to see the cum spurt out and feel it land all over my body, and I sometimes think how I'm going to eat it or how I'm going to rub it all around. But then once I've cum I find I lose interest in those thoughts and I just wipe it up instead unless someone is in bed with me.
P.S. By the way, sorry about the 'jerky' quality of this video =P