Lindsay Lohan kisses a new guy

Things between Lindsay Lohan and her latest paramour, Calum Best have been rocky from the start, with rumors swirling the Calum was hitting on other women behind Lindsay's back. But with Calum back in London and Lindsay back in Los Angeles, the fiery actress isn't about to waste her time pining after him. The word is that she's already seeing someone else.

Lindsay debuted her newest fling Monday night at Hollywood hotspot Winston's. A witness told Star magazine that Lindsay was getting pretty close to a man in a black shirt and black hat that night. The snitch said, "They sat in the back corner of the bar, Lindsay was drinking water, and looking very happy. At one point Lindsay and the guy were necking with each other! She would come up for air once in a while with a huge smile, but then dove back in for more."

Later on, Lindsay invited the mystery man to come back to her place to continue the party. He acted coy, smiling rather than giving his kissing partner a real answer.