If I wear a dress that has impurity on it after bathing and while my body is wet, should I bathe again? If this dress touches other clothes or a bed bedsheet etc. while it is wet, should I wash everything, or just the dress?

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

If you wear a dress that is stained with impurity and the impurity came in direct contact with your wet body, then you have to wash the spot of your body which the impurity came in contact with only. You do not have to bathe again. If the stained garment came in contact with a pure garment and one of them is wet, then according to many scholars, the impurity is transferred to the pure one. Some scholars held that the impurity is not transferred unless the water squeezed out of the pure garment is impure. This is the view of the Hanafis.

In any case, if you are certain that the stained dress touched a ritually pure object and one of them is wet, it is safer to wash the spot that came in contact with the wet part unless you suffer from Waswaas (devilish/obsessive whisperings). If you do, then you may act upon the less stringent view, which holds that the impurity is not transferred in this case. You must also beware of Waswaas and not pay any attention to it.

Allah knows best.