Bianca would, indeed, keep going as long as Ivy could, clearly enjoying returning the favor as spectacularly as she was. If Ivy passed out, though, she'd awaken a short time later, a vial of some terrible smelling substance held close to her nose, shocking her back to consciousness, and giving her a sudden burst of energy and alertness. Otherwise, she'll stop when Ivy stop climaxing, slowing to a stop, before kissing her and pulling it out.