I'm the same, I certainly get nervous for every new girl and mostly even for regulars, it's bizarre the difference between planning it with a hard-on and the lack of any actual desire to fuck when you're travelling there - but I go through with it as a matter of principle and once I'm there it's fine. I too have yet to COF, this is probably because it's also extremely fulfilling to let your hips do all the work, but one day ...