Champions Online

One of the bosses, a supervillainess called Medusa, apparently acquired her psychic powers by seducing a scientist. She has a blown kiss attack that stuns the player in a similar way (complete with hearts dancing around their head). This is the best video I could find I'm afraid. It's a bit of a clusterfuck, but it does display the attack. Every other vid either has the player blocking the attack or has awful music playing over the game audio.

https://www.youtube.com/watch?v=8adWuLwZ3T4