How much have you used this saddle before? Any saddle is going to hurt
if you're not used to riding that far in it.
if you've only gone on 25 mile rides before, asking your delicate underside
to withstand 100 miles is asking a bit much.

More details please? I personally hate my terry butterfly, after 25 miles
I could not sit on it anymore... I replaced it with a leather brooks saddle.