Annie had always had a thing about her friend Katie, and she told me they had indulged in mutual masturbation sessions a couple of times. We were at Katie’s flat having a few glasses of wine and a fun evening. I was chatting to Katie and her boyfriend when Annie went to the bathroom.

As she was taking a while, I went to see if she was OK. I knocked on the door but there was no answer. I tried the lock and it opened, revealing Annie stripped down to her bra and panties. I didn’t recognise them. They were shiny emerald green, cut high and revealing at the sides. The bra didn’t match and must have been her own. She looked a bit flustered but clearly turned on. I closed the door and fumbled with the catch.

“You ok?”

Annie pulled me to kiss her in answer and sneaked her hand down over the flimsy panties, finding her readily accessible fanny.

“Where did you find those pretty knicks, then?”

“They’re Katie’s, I found them on the radiator but they’re dry. Or they were...I’ve always loved this style and I couldn’t resist trying them on,” she confessed.

My hand joined hers over the silky green material where I found her fingers busy about their intended task. Annie pulled the skimpy material back and forth over her crotch emitting little gasps. She was obviously turned on by the naughtiness of the situation. What would she have done if her friend had walked in on her? I was past caring. I sank to my knees and began licking her through the green silk. It was so easy to access her clit through the now sopping-wet material. The panties smelled of a heady mixture between her cunt and Katie’s perfume.

Annie propped herself up against the bath as her knees began to buckle. She humped her hips against my face pulling me to her as she ground her cunt, wrapped in her friend's knickers into my mouth. With a mixture of gasps and giggles, she flooded my face with her juices as I slipped my tongue up inside her.

When she had finished coming she wriggled the borrowed panties off over her lovely milky thighs, gave them a rinse and arranged them back on the radiator to dry.

“What if she suspects?"

I was amazed by her lack of concern.

“Don’t worry, it won’t be the first time I’ve used her underwear,” she giggled. “Katie said she’d buy me some like those for my birthday anyway. Probably just like hers.”

We joined Katie and her boyfriend back on the sofa and Annie winked at her friend as they exchanged a secret smile.