FSET-420 Secretly do it with her best friend so she won't find out! 7

I was daydreaming about doing something naughty with my girlfriend's best friend just once, and then her best friend started glancing my way. Could it be that she has feelings for me too?! While I was thinking about that, her best friend confessed to me, "I've liked you for a long time..." Those words fired me up, and I ended up having sex with her best friend in secret, trying not to get caught!