Hi, girls!
I've never been in the situation 
Nevertheless, I'll try to respond, keeping that unpleasant scenario in mind.
If I ever went to a party and overheard someone talking badly about me, there are only two things I can think of doing:
The first is to leave again. It's the most obvious thing that comes to mind. I don't want to be where I'm not wanted. I don't want to be where there's a negative atmosphere like that. I also don't want to be where someone is trying to hurt me.
Part of my philosophy is to distance myself from all evil and anything that could be negative for me or my loved ones.
I wouldn't be able to enjoy the party in that atmosphere.
The other option would be to approach them so that whatever they have to say, they say it in front of me. It's not a confrontation; I don't intend to fight with anyone (I never have). What I want is to hear what they have to say. Of course, that's assuming they're capable of saying to my face what they say behind my back.
That's not the best option. I don't support violence. But it's a way to silence those cowardly acts (because that's what they are) by giving in to the... Subject.
These situations will always be unpleasant. I don't believe there's a wrong decision, except resorting to violence.
I'd have to be in that situation to really know what I would do. However, the more I think about it, I believe I would leave. I will never give value to empty words and negative attitudes.
Versión en español
Hola, chicas!
Nunca me he visto en el caso que expone
Sin embargo, trataré de responder, pensando en el desagradable supuesto.
Si alguna vez entrara a una fiesta y descubriera a alguien hablando mal de mí, solo hay dos cosas que se me ocurre hacer:
La primera es volver a irme. Es la más obvia que me viene a la mente. No quiero estar donde no me quieren. No quiero estar donde hay algún ambiente negativo como ese. Tampoco busco estar donde haya alguien queriendo hacerme daño.
Parte de mi filosofía es alejarme de todo el mal y lo que pueda ser negativo para mí o los míos.
No podría disfrutar de la fiesta en ese ambiente.
. Lo que busco es que escuchar lo que tienen que decir.
Claro está, si es que son capaces de decir de frente lo que dicen a mis mis espaldas.
Esa no es la mejor opción. No apoyo la violencia. Pero es una forma de callar esos actos de cobardía (porque eso es lo que es) al darle el pecho al asunto.
Estas situaciones siempre serán desagradables. No creo que haya una decisión incorrecta, excepto acudir a la violencia.
Habría que estar en esa situación para saber realmente lo que haría. Sin embargo, por más que lo pienso, creo que me iría. Nunca le daré valor a palabras vacías y actitudes negativas.