Nick Lachey  and Vanessa Minnillo  were in Mexico today, already toasting their futures after getting engaged near the beach in California yesterday ! She flashed her huge asscher-cut diamond ring while holding a "celebrate 30" balloon ahead of her milestone birthday coming up on Nov. 9, the same day Nick will turn 37. The pair started dating back in 2006, shortly after Nick divorced Jessica Simpson  in late 2005. Nick and Vanessa have been on and off  over the years, but they're now looking forward to a "wonderful future together."  Nick took to Twitter  to share his excitement and thank his fans for their support and love, but it sounds like one person who might not be thrilled at the news is his ex Jessica .