Jame's traded away his Victreebel to the Magikarp Salesman in the Johto Region for a Weepinbel that knew SweetSent to try and lure pokemon into their grasp.
In the episode Here's Lookin' at You, Elekid, James is pushed into trading his Victreebel for a Weepinbell by Jessie and Meowth after the Magikarp salesman cons them by saying they can use its Sweet Scent to catch Pokémon.
Later in the same episode, the Weepinbell evolves and bites down on Jessie, causing her to command Arbok to send the flycatcher Pokémon flying off into the distance. At the same time, the Magikarp salesman realizes that James's Victreebel will not obey him, and he kicks it away as well. The two Victreebel meet, fall in love, and skip off together into the forest.
Source (Even though I knew this off the top of my head): http://bulbapedia.bulbagarden.net/wiki/James's_Victreebel
Hope this helps!