Tom Sandoval cries while filming 'Vanderpump Rules' at SUR

Returning to his 'Vanderpump Rules' cast members hasn't been smooth sailing for Tom Sandoval: New video shows him breaking down on their first night together, but you have to wonder if he's it's about crocodile tears.

Witnesses tell TMZ... Tom was chatting with his jeweler friend Kyle Chan at SUR on Tuesday night in WeHo. As we reported, the entire cast - except Raquel Leviss - was there, and around 9 p.m., things took an emotional turn.

Watch the clip, Tom begins to wipe away his tears, but it's hard to say what moved him. Ariana Madix was only a stone's throw away from him, so that could have been a factor.

TMZ.com

Another possibility, however, is that...the producers told him to look distraught. The lighting wasn't great, so we're not going to vouch for the authenticity of this cry-sesh. It's you calling!

On the other hand, Ariana looked pretty happy and was chatting with the ladies at the same time as Tom was crying -- but separate "VPR" cameras were rolling on both stages.

Remember, Tom, Ariana and other cast members all walked into SUR to watch James Kennedy DJ and have dinner with Lisa Vanderpump...marking the first time this season that the entire cast has been seen under the same roof.< /p>