3:14 PM PT — Cardi B is speaking out against the lawsuit, saying she’s going to fight it in court.

Cardi just broke her silence on social media, saying in part … “IRON YOUR BEST SUIT BITCH I’ll see you in court!!!!”

Cardi B is denying she and Offset didn’t pay to use the mansion, and she says she has receipts. She says she paid the homeowner $10,000 for 24-hour use of the home, and paid a realtor more when they went over time.

Cardi adds … “And this is not the realtors fault…they been trying for months to settle this. Its them greedy owners wit their ugly ass house.”

Cardi B and Offset might need to cough up some “Money” … we’ve learned the estranged spouses have been sued for nonpayment for the mansion used in one of their music video projects.

In new court documents obtained by TMZ … the owner of the property featured heavily in Cardi’s “Like What” music video — which Offset directed — is alleging the twosome lied about their filming plans … leading the homeowner to give them free use of the manse.

As the plaintiff put it in the docs … Cardi, Offset and their team knew they’d have to shell out a chunk of change to film at the prestigious Beverly Hills residence for a music video … so, instead, reps for the couple told the owner an unnamed client hoped to film a TikTok video at the home.

Based on this information, the homeowner says he let them use the property — which was previously rented by Justin Bieber and featured in a Logan Paul music video — for basically free … forgoing the usual short-term rental fee.

The owner says had he known the truth about the music video, he would not have waived the rental costs.

The home is prominently featured throughout the entire “Like What” music video … which has been uploaded to YouTube and has earned over 27 million views in 6 months — meaning Cardi and Offset have definitely profited off the footage.

The owner of the mansion is seeking damages in the excess of $35,000.

The lawsuit comes during a trying time for Cardi B and Offset … who just welcomed their third child together, a baby girl, amid their ongoing divorce. It’s been a complicated summer for the two, to say the least!!!

We’ve reached out to reps for Cardi B and Offset … so far no word back.