They try it in Willow's "kitty"

Willow gave a quick kiss to the sensitive head of Tara's new cock, giggling naughtily as it twitched. "It's a new look for you, sweetie; but I like it, as a change of pace." She clambered up onto the bed, spreading her labia in an inviting manner as she tickled her clitoris. Tara leapt up and began to devour her lover's juices with an eagerness that left Xander harder than before.

Tara grinned. "Oh, wow, babe; you seem to be enjoying our little adventure, even without 'Mr. Pointy' here!" Willow groaned at the pun, but was finally unable to contain another giggle. This quickly shifted to a gasp, as Tara continued to trail her tongue up Willow's crotch, and then to a loud squeal of pleasure.

Willow grabbed Tara's head and pulled her up for a fierce kiss, accompanied by a surprisingly competent handjob on her beloved's loaner cock. As Tara moaned with startled pleasure at the new sensations, Willow pulled herself loose from Tara's mouth. "Listen, sweetie, we only have so much time. I want to see what my lovergirl can do with her new cock. Naughty Willow needs some girliecock in her kitty. See the way kitty's smiling? She's waiting for her new playmate to feed her some special meat." They both giggled at that one.

Tara, without warning, shoved her new toy to the hilt into Willow's moist "kitty"! This time, the gasp was succeeded by a deeply erotic groan. Whatever experience Willow did have (she'd always been reticent about that), this was clearly more 'special meat' than she was used to. "Yes, sweetie, yes! Willow needs her DoubleMeat special. Give me one with everything! That's it; that's what momma wants!"

"Tara seemed to be getting pretty good with her new attachment," Xander thought from his spot in the invisibility 'closet.' "I haven't even needed my powers to have fun. But maybe I need to join in now..."