It’s been three years since Lauren Silverman ditched her husband and became Simon Cowell’s baby mama.

This week, the glam duo were reported arguing in London where they celebrated Cowell’s 57th birthday this month.

Now the couple’s former Upper East Side digs are on the market for $5.99 million.

The three-bedroom (with the option for a fourth) duplex at 1055 Park Ave., a super-chic boutique building at East 87th Street, is 3,212 square feet.

We hear the unit is still furnished the way it was when Cowell and Silverman rented it and, for an added price, the seller is willing to part with the furnishings as well.

The unit features floor-to-ceiling windows, a corner living room, a formal dining room, a chef’s eat-in kitchen, and “a sculptural stairway with frosted glass steps mounted on cascading white risers,” according to the listing.

The unit is also smart-wired and boasts wide-plank oak floors.

Building amenities include a gym and — the best part — a sort-of secret, paparazzi-proof side exit door that came in handy when the lovebirds were trying to avoid the media. The listing broker is Douglas Elliman’s Tristan Harper.