Did she use me? (NSFW)

Hi,

I had sex with my girlfriend friend today for the first time and i finished too quick. She didnt seem too impressed but she didn’t moan.

Anyways, she later texted me on WhatsApp saying she feels “guilty” and “like shit” and none of that should have happened and she needs time etc…

Why does she feel guilty? Did she use me for sex or was she very disappointed in our sex that she feels guilty?