Guys i think i fucked up

So last April me and my gf started renting a house with her sister and her bf (we are all in our 20s). Well last month they broke up leaving myself, my gf, and her sister. Let's call her Jessica.

This morning, since i didn't get any last night, i was gonna jerk it before i got in the shower. Turn the coke water on so it sounds like in the shower watching porn on the toilet. My gf went to work her sister asleep in bed. Jessica woke up and walked into the bathroom to get her tooth brush finds me jerking it. She's like wtf I'm like wtf she leaves i go limp shower and go to my room super word vibe.

She knocks on my door after i got dressed wearing only a towel and says "annon I've had an ich i need scratched and i see you do to let's help each other."

So i fucked her on me and my gf's bed. The guilt is overwhelming. I want up throw up but she seems fine with it.

Holy fuck guys I'm a total ass hole. Need help. How do i get rid of this guilt.

InB4 telling my gf not trying to be homeless