Machine Gun Kelly's Guitarist Blasts Claims They Had An Affair

Machine Gun Kelly's guitarist is calling BS on reports she had a romantic liaison with MGK ... after folks online claimed she's the reason for the singer's alleged breakup with Megan Fox.

The management team for guitarist Sophie Lloyd spoke out about the recent allegations ... telling Page Six she's "been needlessly dragged into the media based off of meritless accusations made by social media."

Her team went on ... "Any suggestion that she has ever acted in an unprofessional manner or stepped out of her relationship are untrue."

MGK and Sophie have been rocking together on tour, starting back in May of last year ... but fans started speculating they were an item.

As we reported, Megan scrubbed all photos of her and MGK off her IG over the weekend, while posting pics of an envelope burning with the caption, "You can taste the dishonesty it's all over your breath" -- a song from Beyoncé's Lemonade album, "Pray You Catch Me" ... the album which chronicles Jay-Z's alleged cheating.

She ended up deleting her account altogether ... but with cheating allegations in the air, fans are pointin' fingers at Sophie -- who's also in a relationship.

MGK and Megan were spotted together on Valentine's Day ... so all this hoopla might just be a bump in the road ... maybe they're working things out.