I agree with @Blamelesscars - I don't blame Jake but he's a complete snake and acted friendly to the girls all the while knowing he'd been encouraging their guys to get with other girls. Given how loyal Liberty seems to be, it's not something I expect she'd approve of and reckon she'd actually be upset by his behaviour.
Still totally blame Liam and Tyler though - just because someone eggs you on, doesn't mean you have to act on it!