Dave Grohl was branded ‘crazy’ by his wife Jordyn Blum after he accused her of having a ‘flirty’ relationship with her tennis coach in a series of furious rows – before confessing to his own infidelity.The Foo Fighter’s front man, 55, shattered his ‘nicest guy in rock’ image this week when he revealed that he had recently fathered a child with another woman in a bombshell admission posted to his Instagram.But in the months leading up to the shock announcement, a ‘jealous’ Grohl had been grilling Blum, 45, on her relationship with her ‘hot’ coach, Christopher Crabb, 54, in what insiders claim was an attempt to detract from his own indiscretions.‘Dave Grohl has been jealous for ages about Jordyn’s hot tennis coach,’ an insider told NEWSWALLA.com exclusively.‘They’ve had arguments about him, and Dave thinks they’ve flirted. Jordyn has told him he’s crazy to even think that. But Dave has persisted.’ Dave Grohl was branded ‘crazy’ by his wife Jordyn Blum after he accused her of having a ‘flirty’ relationship with her tennis coach in a series of furious rows, insiders claim  A ‘jealous’ Grohl had been grilling Blum, 45, on her relationship with her ‘hot’ coach, Christopher Crabb, 54 (pictured) before confessing to fathering a child with another woman Blum has been training with Crabb for years, sometimes having up to three sessions a week at his $1.4million Tarzana property where he coaches celebrity clienteleBlum has been training with Crabb for years, sometimes having up to three sessions a week at his $1.4million Tarzana property where he coaches celebrity clientele from Pete Wentz to Hillary Duff and Zach Braff, on his bright blue court.Other star clients include Donald Faison, Jeff Probst, husband-and-wife duo Nancy and Steve Carell, siblings Elle and Dakota Fanning, and Grohl who has had lessons.The tanned, blonde-haired coach regularly posts tennis tip videos, featuring his dog Sierra, to his Instagram account which has just over 2000 followers, one of whom is Blum.The ex-model and producer has featured in several clips, with Crabb referring to her as a ‘great student.’‘I’m here with Jordyn Grohl one of my really great students,’ he says in a clip from October 2022. ‘She’s really solid.’Blum, who has been playing tennis for seven years and competes in leagues, can be seen wearing her signature dark glasses, a black tennis skirt, a pink Fila t-shirt and is flashing her engagement ring.One month later he roped her in for another video – set to the Foo Fighters’ hit Learn to Fly – and asked her to demonstrate a ‘Loop vs straight take back.’In July he posted a picture of Blum and Grohl together at Wimbledon and wrote: ‘So excited to see my students, Dave and Jordyn. They always look stylish on and off the tennis court.’ ‘Jordyn now believes that Dave has been trying to detract from his own indiscretions by accusing her,’ an insider told NEWSWALLA.com  The tanned, blonde-haired coach regularly posts tennis tip videos, featuring his dog Sierra, to his Instagram account which has just over 2000 followers, one of whom is Blum Blum (left) pictured next to Crabb for a birthday celebration with fellow clients in 2022But according to the insider Grohl has ‘been jealous for ages about Jordyn’s hot tennis coach.’‘They’ve had arguments about him and Dave thinks they’ve flirted,’ they added. ‘Jordyn has told him he’s crazy to even think that. But Dave has persisted.’They continued: ‘She gets coaching at least three times a week near the family home. Jordyn now believes that Dave has been trying to detract from his own indiscretions by accusing her.’The source insisted there has never been anything remotely romantic between the pair. NEWSWALLA.com has contacted representatives for Grohl and Crabb for comment. Grohl and Blum’s seemingly solid 21-year marriage was shattered this week when he revealed he has fathered a fourth daughter with an undisclosed woman.The former Nirvana drummer shares Violet, 18, Harper, 15, and Ophelia, 10, with Blum.’I’ve recently become the father of a new baby daughter, born outside of my marriage,’ he wrote in a statement posted to Instagram on Tuesday. ‘I plan to be a loving and supportive parent to her.’I love my wife and my children, and I am doing everything I can to regain their trust and earn their forgiveness. We’re grateful for your consideration toward all the children involved, as we move forward together.’Blum is being consoled by her close friend Kate Hudson, who is on call ‘24/7’ and has offered to move in if she needs it in the wake of the fall out.Less than 24 hours after Grohl’s post was shared an Instagram user with the name @valeriegreyston posted a picture of a baby, allegedly called ‘Roxie Junie Grohl,’ who they claimed was Grohl’s lovechild. Blum and Grohl attended the 2023 Grammy Awards with their daughters (L-R) Harper, Ophelia and Violet in Los Angeles, California Pictured: Christopher Crabb while starring in the film Church vs State in 2016However, a representative for the former Nirvana drummer told TMZ that it is fake.Grohl’s alleged close relationship with porn website founder Annaliese Neilsen has also come under scrutiny as fans make desperate attempts to identify the woman.It is not the first time the rocker has cheated, having admitted to infidelity during his first marriage to Jennifer Leigh Youngblood. The pair were married for three years before their split in 1999.He then dated Louise Post from the band Veruca Salt – who accused him of cheating on her with actress Winona Ryder and a handful of other women.He appeared to cement his status as a ladies man in 2002 when he confirmed he ‘did’ groupies.’Groupies come to the back,’ he told The Face. ‘They know what they want; they know what the band wants. It just happens. It’s that easy.’