A new study from London says touching your phone between using the toilet and washing your hands is a very bad idea.
That's because toilet seats, handles, and the sink are covered in germs, such as e-coli.
Researchers suggest washing your hands frequently in public toilets.
Using your phone in public toilets can also have lingering effects.
The flu virus dies in minutes, but the norovirus can survive for several weeks on a dry surface, such as a cell phone.