'Married at First Sight' Stars Madison & David Are Engaged After Cheating Scandal

"Married at First Sight" stars Madison and David are engaged ... after beginning their relationship with a bombshell cheating scandal.

Madison shared the news on her Instagram Stories, posting a video of David popping the question in a crowded restaurant. In the clip, Madison's jaw drops as David suddenly gets on one knee with ring in hand. Onlookers were also stunned by the sweet moment.

In another post, Madison shared images of a surprise St. Patrick's Day-themed engagement party.

Remember ... viewers watched the couple's romance bloom during season 18 of 'MAFS' as Madison developed feelings for David while she was married to Allen and David was married to Michelle.

Despite the cheating scandal, David and Madison pushed forward with their relationship and -- against all odds -- it appears to be working out!