My stepsister breaks up with her boyfriend and now she wants to have sex with me again since we trust each other

I have plans to see my girlfriend, but my stepsister broke up with her love affair and wants to have sex... Weeks ago we had sex and she decides to seduce me to get some action... I try to explain to her that my girlfriend is coming and I must tell my girlfriend not to come and go quickly to the room to penetrate my stepsister's delicious and tight pussy!