Cycling shorts are a must for riding for more than 60 minutes and they will help a lot with chafing, but it will remain that your derrière will be seated on a relatively hard saddle. (Cushy saddles are not necessarily more comfortable.)

You will partly develop resistance to it (including stronger butt muscles). And partly still feel it when you will pay attention. But it is normal that it takes a couple of rides to feel better about it just because you don't notice anymore. (I know it sounds weird at this time...)

Most of the pain will go away but, at the end of your first century (you WILL ride one some day sooner than you think - trust us!) I swear that your derrière will still hurt a bit like mine was hurting last week!!!

By the way, I suggest everybody read the Bicycling Magazine latest issue paper on very-plus-size riders. Very interesting. Too bad: only men as usual. Maybe we could write a letter to the editor and suggest they make more efforts to include women in their articles in the future.

Cheers!