Is Sofia Vergara hesitant about being engaged to businessman Nick Loeb even after accepting an 8-carat ring worth several hundred thousand dollars? Sources tell us that since he popped the question in front of her friends and family in Mexico, the gorgeous “Modern Family” star has been wearing the stunning diamond ring he bought her from Long Island’s London Jewelers. “Extra” reported that while Vergara accepted the ring, she hasn’t fully accepted his proposal. But Onion Crunch king Loeb insists they did get engaged as they celebrated her 40th birthday at the Rosewood Mayakoba resort in the Riviera Maya. We’re told he presented Vergara with the huge sparkler from the Manhasset jeweler’s Two by London collection. Store owner Scott Udell said Loeb approached him two weeks ago to design the ring, which he delivered before they left for Mexico. Udell said, “I worked with Nick personally to design the ring, and we tried to make it a reflection of Sofia. It is a beautiful three-stone ring. The center stone is square, a 7-carat cushion-cut diamond. It has two diamonds on the side, and the brilliance of the three stones together makes it look like a 10-carat ring.” Representatives for Vergara and Loeb, who were traveling back from Mexico yesterday, declined to comment.