The happy moment took place while the couple were holidaying in Fiji.
Laura also spoke of the joyous news, gushing, "You are my favourite everything @matthewdavidjohnson. YES to a lifetime of love and flamboyant dance moves with you my honey."
MJ proposed with a beautiful bespoke pear-shaped diamond ring, created by Larsen Jewellery.
Many ex-Bachie pals congratulated the pair.
Jake Ellis said: "Yessssss!!! Congratulations brother! Amazing news for you both 💕"
Fellow married Bachelor Sam Wood commented, "Awesome news guys !! Xxx Kept that a secret last week 😉"
But it was Laura's comment that all of us smiling, "I DON’T CARE IF WE ARE SITTING NEXT TO EACH OTHER ON THE COUCH, I FREAKING LOVE THE SHIT OUT OF YOU - My fiancé ❤️"