Dina Lohan is currently in Rancho Mirage to be with Lindsay during the Betty Ford Center's Family Week. However, Michael Lohan says Dina missed orientation day and instead, hung out with a best friend at the pair's hotel with a couple bottles of wine.

He tells us Dina left her Palm Desert hotel with a gal pal "all dressed up to enjoy a night of partying," according to a friend who saw her and texted him, but when she spotted photographers, Lindsay's mom ducked into a local CVS store to pick up some party supplies instead of hitting up a bar. Michael says she left about 15 minutes later, according to his eyewitness, who saw her exit the store with "big bottles of wine" that she and her friend took back to the hotel.

Michael tells X17online exclusively:

    "I can't believe Dina claims she's there to help Lindsay get back on track, and she goes out drinking the day before visiting her daughter in rehab. Clearly, she's in this for herself. We already know she was trying to get camera crews to go with her while she went to Betty Ford. People don't realize that she's making a killing off of Lindsay's set-up shots. It's all about money to her."

Dina Lohan did not return our request for comment.