Old MacDonald had a harem

THE bass player from red-hot band The 1975 found himself at the center of a rather unseemly early-morning tug of war of sorts between two ladies, Page Six is told.

After the band performed on “Saturday Night Live,” we’re told Ross MacDonald hit up two after-parties, where he was quite the hit with the female revelers.

A spy spotted the 33-year-old rocker making out with a new friend at Gramercy cocktail hot spot Dom, where they were still partying as the sun rose at around 7:30 a.m.

But trouble brewed when another woman purposefully approached the pair to extract MacDonald — much to the distaste of his smooching partner.

The interloper “came up to him and said, ‘Let’s go!’ ” before walking away with the musician, our spy said.

“And then the [makeout partner] was really loud and was like, ‘What are you doing?’ and was following them and saying all this weird s - - t,” the source added. “The sun was out! It was cuckoo.”

And well she might have been, since it sounds like she’d put the work in to bag her Brit bassist.

We’re told that earlier in the evening, she had been “dancing and flipping her hair all around.”

“There were quite a few women interested in talking to” MacDonald, said one person who got down at the new speakeasy.

Earlier that night, the band had partied uptown at Hutong with some “SNL” cast members and the evening’s host, Jenna Ortega, before the extremely late after-after-party at Dom. We’re told Ortega was flanked by security and “was in and out” of the pricey Midtown dim sum spot.

“She ate and left out of a side door,” a source, who attended the late night dinner, told us.

Lorne Michaels held court at a Hutong table with former “SNL” star Fred Armisen, we’re told. Meanwhile, Ego Nwodim, who had a birthday Friday, shimmied her way out of the spot at night’s end, “dancing in the courtyard with friends,” our source said.