A quickie recheck with Google image search finds a couple of additional Prinet works, and information that he specialized in landscapes. There are one or two pencil/chalk sketches up in the result that I don't recall seeing when searching a couple of years back, but nothing very interesting.

I did chance upon at least one passionate kiss:

Jean Coraboeuf: Pygmalian. The page will open on page 4 in French. You can click on the Brit flag to get an English version, but that will take you back to page one. On page 4, the second picture is definitely your passion kiss. Click the picture to enlarge twice for best effect.

It's an obvious ripoff of the Jean-Léon Gérôme work at the Met, from about 50 years earlier, although neither gives a date that I found. But a bit more "sexified."

Previous searches for Prinet found him only as "René Xavier Prinet" but one new Google hit says he had a middle name: "René François Xavier Prinet" so maybe we need to look for Frankie Prinet instead of just for Rene.

John