Ray J and Princess Love got into a heated fight … and we’re told things were so bad, police got involved and detained Ray in the back of a squad car.

Law enforcement sources tell TMZ … Ray J came home from a tour Thursday afternoon and he and Princess Love started fighting about their pending divorce.

We’re told Princess called LAPD, claiming Ray J was being aggressive, yelling, and possibly under the influence.

Why pick between booze n’ coffee when you can have both?! It’s National Espresso Martini Day indeed and the trendy drink has stirred up some trouble in Hollywood … Come pour one up with these sippin’ celebs!

Sarah Michelle Gellar was a total martini vibe happily posing with her ‘tini, Sabrina Carpenter had herself a brew-tiful evening with Taylor Swift and Rina Yang … and Nick Jonas was bold n’ buzzed as he cheers’d to the bean!

And, perhaps the bougiest Housewife, Heather Dubrow has pushed her go-to ‘champs’ to the side and in its place: a stellar espresso martini!

Martin Kove is thrilled his old pal Sly Stallone has become a Hollywood ambassador via President Donald Trump … ’cause he thinks the town has lost its magic by becoming too political — and who better than “Rambo” to straighten things out?

TMZ caught up with the “Karate Kid” and “Cobra Kai” icon at LAX … and he straight-up told us Sly is ready to sweep H’wood’s leg if that’s what needs to be done to bring back some artistic sensibility.

MK is confident Sly — along with Jon Voight and Mel Gibson, also appointed by Trump — will get Hollywood back to making quality entertainment — and get the industry to scrap the soapboxes.