Is pillow humping safe whithout panties?

Yes.

Masturbation is normal and is the safest way to have sex. Just make sure you don't fall off the bed.

If you notice chafing, then you may want to get a softer pillowcase. I think it is safe I mean i do it all the time it's amazing!! * http://wiki.answers.com/Q/Is_it_normal_to_hump_a_pillow