Did they fuck?
did THEY fuck?
Yes. But Kaiki already stole Crab's virginity before Araragi.
How old was Crab lost her virginity?
Fire sisters == yuri sisters ?
Yes, they fuck during Nise after beating Kaiki.
Uso da dese
>he didn't saw the BD specials
okay but the fire sisters are yuri for each other?
Yes, but she was used goods by that point.
It's also implied that Araragi and Shinobu have also done more than just take baths together.