She’s been married to Ryan Phillippe, had a long term relationship with Jake Gyllenhaal, and now she’s with Hollywood agent Jim Toth. Reese Witherspoon reveals to ET how she gauges who is right for her relationship-wise.

“I’m old enough to know that I don’t know anything about love or relationships,” she disclosed. “I just try to go with my instincts and advise other people to do the same.”

The ‘How Do You Know’ star did admit that she has a way of determining whether her relationships are going to work out. “My friends are a barometer for my relationships,” she told ET. “I kind of look at them to reflect to me how I seem.”

In her upcoming movie written by Oscar winner James L. Brooks, Reese plays Lisa who is caught in a laughable love triangle. Lisa faces a difficult transition in her life, and jumps into a relationship with the self-centered Matty (played by Owen Wilson). Then she meets George (played by Paul Rudd), a man who’s facing financial ruin and a federal investigation for shady deals made by his father’s (Jack Nicholson) company. ‘How Do You Know’ hits theaters Dec. 17.

Watch the video for more from the cast including Paul’s admission of snapping some “naked butt” pics of his co-stars.