Lindsay Lohan isn't offended that The Wanted singer Max George completely denied their relationship on Twitter this week -- because as far as she's concerned, there IS no relationship ... they're just hook-up buddies.

Lindsay posted the above photo on Instagram a few days ago -- showing her and Max joking around together -- and Max's fans erupted on Twitter ... writing things like, "If you date Lindsay, I will die!"

Max responded to the complaints, flat-out denying he was dating Lindsay whatsoever -- and called speculation about their relationship "rumors ... That's all ... Like I said ... 1 million percent."

But Lindsay's telling friends, she doesn't feel burned -- because Max is telling the truth ... they aren't boyfriend and girlfriend ... they just have a no-strings-attached non-exclusive hook-up thing going on.

We're told Lindsay is not taking things seriously with Max at all -- she just likes hanging out with him -- and he's free to tweet whatever he wants.

Things are getting super serious between Lindsay Lohan and Wanted singer Max George --'cause TMZ has learned he just took her home to meet his parents in the U.K. ... and we're told it went off without a hitch.

Lindsay and Max have been (unofficially) seeing each other since that fateful night in November -- when  she allegedly punched a fortune teller at an NYC nightclub -- but this week, they took their relationship to the next level.

Lindsay's been partying it up recently in London -- as we reported -- and sources close to the actress tell us, Max invited her out to his parents' house in Manchester while she was in the area.

Lindsay happily made the visit early this week -- and we're told Lindsay had a great time, hanging out with the whole George clan for an entire day ... and she felt very at home.

We're told Lindsay and Max have been in constant contact since the last Wanted concert Lindsay attended last month (in the U.S.) -- and Max was adamant about her meeting his family.

As of now, we're told Lindsay and Max are NOT officially GF and BF -- just friends who enjoy each other's company ... and probably bang each other a lot.

Lindsay Lohan staked her claim to new beau Max George from The Wanted ... throwing her arm around him at a club in New York City last night following their show at Madison Square Garden.

As TMZ first reported, Lindsay has been by Max's side the last few days, even riding with the band on their tour bus. We're told Max has been the aggressor in the "relationship" from the start, but that Lindsay isn't looking for anything serious right now.

Which is probably for the best ... she might be a little busy for the next 8-12 months.

Lindsay Lohan insists ... she didn't make the first move when it came to hooking up with The Wanted singer Max George ... he was the aggressor from the start -- but Lindsay's not complaining one bit.

Lindsay's telling friends, Max pursued her from the beginning -- flirting with her aggressively since that fateful night last week at the club Avenue in NYC, where Lindsay allegedly punched a fortune teller.

Lindsay also says Max is the one who invited her backstage at Jingle Ball in Philly this week ... and he's also the one who invited her to join The Wanted on their tour bus.

But we're told Lindsay's happy to go with the flow -- because she really likes Max and enjoys hooking up with him ... even though she's not looking for a serious relationship.

The reason ... Lindsay believes she has lots of work to do on herself before she ropes someone else into her crazy life.

She's got a point.

Lindsay Lohan has risen to super-groupie status -- and must be banging Max George -- because TMZ has learned she hit the road with The Wanted ... on their tour bus!

Sources close to Max tell us Lindsay is in Boston with The Wanted for their Thursday night show -- and we're told she got there riding first class on board the group's luxury bus ... as Max's guest.

We're also told Max is now 'fessing up he did invite LiLo backstage for the Philly Jingle Ball last night.

While Linds hitching a ride with Max is pretty strong evidence she's got her hooks into him -- our source says Max definitely "doesn't want a girlfriend, and is a single guy ... but doesn't mind having Lindsay around."

Not exactly Romeo and Juliet ... but we're guessing Lindsay will take it.

The Wanted singer Max George is 100% not dating Lindsay Lohan -- sources close to the heartthrob tell TMZ -- but no one seems sure of exactly how she got backstage at Jingle Ball last night in Philadelphia.

As we reported, Lindsay was spotted signing autographs at the concert -- but according to our Max sources, IF he invited LiLo ... he's not owning up to it. We're also told Max had no idea she was planning to come.

It's unclear if the two made contact while Lindsay was backstage -- but sources tell us, Max has no desire to be in a relationship right now ... with Lindsay or anyone ... seeing as he only recently broke things off with his ex-GF Michelle Keegan (some English actress).

FYI -- Michelle's smokin' hot. 


So we gotta ask ... 

Lindsay Lohan is still hot on the trail of Max George -- following him ... like a common groupie ... from NYC to Philadelphia last night, and even popped up backstage at a 'Wanted' gig.

Lindsay somehow scored a VIP pass to the Jingle Ball -- where The Wanted performed -- and was seen signing autographs for fans.

Of course, the last time LiLo tried cozying up to Max ... she got sloppy drunk, rejected by the boy-bander, and ended up in handcuffs after fighting with a woman inside of an NYC nightclub.

No word if Lindsay actually got to spend time with her man-crush this time around.

Max from "The Wanted" -- ya know that guy Lindsay Lohan wants to bang -- is officially on TEAM LILO ... because he just told our camera guy (with a straight face) ... "Lindsay's a good girl."

Max (and his boy band) were at LAX  yesterday -- and we asked him all about LiLo's problems ... considering he partied with Linds the night she got arrested for allegedly punching that psychic in the face.

Annnnnd some eye-witnesses said the whole fight started because LiLo was jealous that Max was chatting up another chick (a.k.a the "psychic").

Surprisingly, Max gave LiLo a glowing review ... specifically saying, "She's fine. She's out of trouble ... Lindsay's a good girl."

So we gotta ask ...

One of the guys from The Wanted has Lindsay Lohan's back ... unfortunately for her, it's not the guy she's been trying to bang.

We broke the story ... Lindsay has been gunning to nail Max -- the one with the shaved head -- for the past couple of days ... and partied with the guy at Avenue nightclub the night she was arrested.

But last night, one of Max's fellow boy-banders -- Jay -- let everyone know the guys are still supporting their most infamous fan by wearing a shirt on stage at their concert that read, "Free Lindsay."

As we previously reported, Max rejected Lohan on the night of the fight because she was too sloppy drunk ... and went home with another chick instead.

Lindsay Lohan punched another woman in the face over Max from the boy band "The Wanted" last night ... and we've learned Max was turned off by the fact LiLo was sloppy drunk inside the club ... this according to sources at the club.

We're told ... Lindsay went to the Justin Bieber concert -- but not to see the Biebs -- "The Wanted" was the opening act ... and Lindsay has been scoping Max out for the last few days.

She's not the only one either -- on his way out of his NYC hotel yesterday, Max was swarmed by adoring female fans ... and he even kissed a few.



Sources say Lindsay tried to get backstage after the concert  to see him -- but she was blocked. Fast forward to later that evening when Lindsay met up with Max, Jay and Tom at a hotel bar.

The four of them -- along with one of LiLo's friends -- then went to the club Avenue together.

As the evening wore on, we're told Lindsay got drunker and drunker ... and it turned Max off. He then started talking to another woman, which enraged Lindsay. That woman is the one Lindsay is accused of battering. (FYI -- Max was also really drunk).

Ironically, Max washed his hands of both of them -- found another girl in the club -- and went home with her instead ... while Lindsay ended up in jail.

Two days after calling "Voice" judge Christina Aguilera "a bitch" on the radio in New York, one of the guys from The Wanted seemingly apologized in one breath ... and then took another shot at her in the next.

After a guest appearance on the show, the band went on 92.3 NOW in NYC and said, "She's a total bitch. She might not be a bitch in real life, but to us she was a bitch."

Talking outside the Mondrian Hotel today in Hollywood, the one who calls himself Tom was asked about his Xtina comments ... and in back-to-back sentences he said, "We shouldn't have said it, to be honest with you. We just think manners cost nothing, you know what I mean?"

Neither does humility.