Fans noticed that the man holding Hilton's birthday cake is none other than actor Chris Zylka. Hilton and Zylka appeared to share a passionate smooch during the festivities.
Zylka, who stars as Tom Garvey in HBO's The Leftovers, has an interesting Hollywood backstory. He was homeless before a manager discovered him while he was working at a restaurant. Aside from The Leftovers, Zylka has starred in shows like 10 Things I Hate About You and Twisted.