Those "lame-pants" are your friend, my friend, at least until your butt toughens up. There's stuff at bike shops called chamois butt'r and so on, or the old standby, Desitin if nothing else.

Rule #1 is keep it clean. I wash my "lame pants" after every wearing in the sink with simple green. Give your butt that extra scrubbing in the shower. The mantra of the professional cyclist is clean, clean, clean.