My friend saw porn on my phone when i lent it to her to get on the internet but it wasnt even me who searched?

What do i do she didnt bring it up or anything i mean likei had no clue until i opened up the internet and it was there then i thought back to how she had said oh well i guess i dont remember the wifi code and gave it back to me now i feel really weird and awkward and sick at my stomach but i didnt even search it or pull it up on my phone it was one of my dumb *** friends who wanted to get on the internet what do i do now .... if i tell her it wasnt me she wont believe me and think im a lier and that will be worse and i feel so stuck and pissed