Miley Cyrus had a special guest in the audience at her concert at the Staples Center Tuesday night – her Last Song costar and real-life boyfriend, Australian actor Liam Hemsworth!

That’s right: BOYFRIEND! A source confirmed that the two have been dating now for almost five months and Tuesday night was their debut as a serious couple. They had no problem showing off their PDA at Miley’s super after-show bash at Katsuya, where people say they were very “lovey-dovey.”

Two noticeably absent friends of tween super star were her bestieMandy Jiroux and ex-bf Justin Gaston. Mandy had a concert of her own to play with her band The Beach Girl5 and Justin decided to sulk out there instead of going to Miley’s gig.

Yeah, we wouldn’t want to see our ex smooching with someone twice as handsome and five times more successful than us either. That’s a heartbreaker!

[Image via WENN.]