'RHOA's Porsha Gets Into A Physical Altercation with Ex-Fiancé Dennis

There's certainly no love lost between 'RHOA' alum Porsha Williams and her ex-fiancé Dennis McKinley ... who got into a shouting match that turned physical.

Porsha, friends and family -- including Dennis -- were all vacationing in Mexico during an episode of her show "Porsha Family Matters" Sunday night ... and things quickly went from 0 to 100 during dinner.

The argument first started earlier in the trip after Dennis was called out for cheating on Porsha when the two were together ... but things escalated at dinner when the fight continued after Dennis told Porsha's cousin, Storm, to back off.

While it starts out verbal, things get physical after it appears Dennis lunged at Porsha. Fists fly, and cast members -- including Porsha's friend Simone -- step in to try and separate the two.

However, fans will need to wait till the next episode to see how things end, as the episode came to a cliff-hanger ending before all was resolved.