Yes...

ENDING NINE: **** is Best (Better than You, Anyway)

When you arrive at Heather's house, you wonder briefly if she'll be ready yet.
But those thoughts are interrupted when you notice Heather's bedroom window is open...
And Veronica is there, tongue-kissing Heather!!

Soon, they stop kissing and go out of sight, but you still hear both women giggling erotically...to each other?!

With maximum caution, you silently sneak in with a spare key and go upstairs.
Although the bedroom door is closed, you definitely make out the sounds of sex! The two sisters...are lovers, also!
Peeking in through a door crack, you spy both women on the bed, a giant double-ended dildo in-between, pleasuring their pussies. It's so, so, so much bigger than your dick...The sisters cum screaming on the dildo and kiss wetly as you slink away into the night.

Your relationship with Heather is over.