Credit: Michael Kovac/FilmMagic (3)

Busy, flirty night for Lauren Conrad!

On Friday, the designer and author hung out with both her ex-boyfriend of three years Kyle Howard -- and Teen Wolf's hunky star Colton Haynes!

My Boys actor Howard, 33, was spotted hanging out with pal Haynes, 23, at West Hollywood's Trousdale. "Colton invited Lauren to come hang," an insider tells Us Weekly.

Conrad and Hayes were first seen exchanging phone numbers at a bash -- and then hitting a club together -- in late July. "She was into him, and vice versa," a witness told Us at the time.

So when Conrad arrived at the table to greet both her ex-beau Howard and potential new guy Haynes, "there was definitely a pause in the room for a second," the observer says.

At a table shared with Conrad's Hills cohort Lo Bosworth and actress Jamie-Lynn Sigler, Conrad and Howard (who split in June) "looked really close and still very friendly," the witness says.

"You wouldn't be able to tell that they were supposedly broken up? In any case, they are definitely friendly exes," the witness adds.

Meanwhile, what's going on with Conrad and Haynes? "Lauren and Colton have been texting as they've both had hectic schedules," the second insider explains.