"Louis is happy and very excited about becoming a dad and he thinks Briana will be an amazing mother," the source revealed. "It was a surprise at first, but he and Briana are very, very close friends and this has brought them even closer."
As ET previously reported, the "Perfect" singer and Jungwirth -- a stylist in Los Angeles -- were briefly linked back in May, just one month after Tomlinson split from his longtime girlfriend, Eleanor Calder. In December, Tomlinson sparked romance rumors with another girl, The Originals star Danielle Campbell, after they were spotted out together in Chicago.
To hear more on Tomlinson's little bundle of joy, watch the video below.