You might be thinking "What a cute photo of Steven Bauer and his daughter," right?

But nope, that girl isn't the "Ray Donovan" actor's kid ... or his niece ... or his granddaughter. She's his girlfriend!

The "Scarface" alum, 57, was spotted out in Los Angeles on Wednesday with his much younger girlfriend, Lyda Loundon. Lyda, 18, is almost 40 years her male paramour's junior ... and also younger than both of his children. 

The actor's son with ex-wife Melanie Griffith, Alexander, is 29, while his son Dylan is also in his mid-20s.

According to her Twitter page, Lyda is a self-described "part-time nightmare-inspirer, journalist, host of Sarcasm Overdose, ceo, film/music/cigar/espresso addict."

Bauer and Loundon have been dating for a couple months now, and stepped out for the first time together for a film screening back in July.

What do you think of the couple's 39-year age difference? Check out more May-December romances in the gallery above!