Opinion on what Emma did at the bonfire?

Whats your opinion on what Emma did at the bonfire? I personally don't like Emma at all because of how mean she is to Jacob at times but what she did at the Bonfire really pissed me off, not only did she do it just to make Jacob jealous but to give Abi 'a little nudge'. Imagine your friend who knows damn well you like a guy sits on his lap and trenches him right in front of you, wouldn't you feel betrayed? Also Dylan said if everyone consents, Nick said it's probably not a good idea and Emma could've just said no to kissing Jacob or Nick, so what's your opinion?