Christina Aguilera:

THE SINGER, WHO'S LONG BEEN RUMORED TO HAVE AN ALCOHOL PROBLEM, IS HITTING THE BOTTLE AGAIN.

Drinking to Excess! Friends are worried the mother of two has fallen back on bad habits and is relying on booze to loosen up amid a hectic schedule.

VINO is What a Girl Wants! Christina Aguilera seemed to be enjoying herself a bit too much during what appeared to be a very wet lunch while vacationing in Italy’s Lake Como. During a boat outing on July 16, she and boyfriend Matthew Rutler stopped at a restaurant in Tremezzo, where the songstress got a little merry as she knocked back some wine. After hitting the bar in a neighboring town — where the drinks also flowed freely — a bleary-eyed Christina was so tipsy and unsteady on her feet that several men had to help her get back on the boat.

The singer, 38, who was in Europe for a string of concerts for her Xperience Tour, has a habit of hitting the sauce too hard. “She’s been boozing for years and doesn’t have a stop button,” a source tells Star. In 2011, she was busted for public drunkenness after Matthew was stopped for driving under the influence and police found her so inebriated that they threw her in jail for her own safety.

In December 2015, pals saw it coming when the “Just a Fool” singer got so sloshed at a party that she nearly crashed into a Christmas tree as Matthew tried to prop her up and get her out the door. A month later, she reportedly passed out drunk in Jeremy Renner’s bed after turning up uninvited to the actor’s birthday bash at his Beverly Hills home. “Friends are urging Christina to get her act together before her drinking spirals even more out of control,” the source says. For her part, the singer has said she “deserves a few drinks after working so hard and looking after the kids.” Indeed, she brought a full wineglass back to her boat in Italy — and took along a few bottles for the ride.