I made my friend’s girlfriend cheat (M)(F)

I had a friend since highschool and in that period we had a steady group of friends. Girls and guys. My best friend got into a relationship with one of the girls, Stella. She was a gorgeous natural girl, brunette, tall, tight body, curves in the right places and a smile that makes you melt. Highschool was over and some of us stayed in touch. My friend and I and also Stella. I always had a crush on Stella in highschool but respected her relationship with my friend. One time I saw their relationship became a little bit of a drag. My friend also told me that a lot of sparks were missing these days. Because of that Stella sometimes was closer to me and old flames started burning deep inside me. 

Stella was almost having her 23rd birthday. My friends told me he got her a laptop, she needed one. I was also thinking about a gift. Because of my information and the fact that I know Stella likes naughty things, I had a naughty gift for her. I went online and searched at a sex shop for a vibrator with excellent reviews. I found one and ordered it. They delivered on time, I wrapped it up and on her birthday I went to her office and gave her the gift. I put a note on it that said she could only open it when she was alone.