Jennifer Lopez is ready to dump her boy-toy Casper Smart following further lurid claims that he’s been sexting transsexual models behind her back. 
 
 Sources said Lopez, who is preparing for Wednesday’s free concert in front of thousands at Pelham Bay Park and also appeared in The Bronx to promote a healthy eating initiative, is furious that Smart’s alleged extra-curricular activities could overshadow her work. 
 
 On Sunday, “Jenny From the Block” appeared at the Bronx event to promote the Center for Healthy Childhood at the Montefiore Medical Center, which received $250,000 from her Lopez Family Foundation. 
 
 But on Monday, thedirty.com hit Lopez, 44, with details of 27-year-old Smart’s second alleged sexting transgression, this time with a transgendered female model named Xristina Marie. 
 
 A source told us of the growing frustration in the Lopez camp over Smart’s antics: “She’s coming back to The Bronx and the only thing anyone can talk about is her toyboy and the transsexuals.” 
 
 Another source tells us, “Jennifer is getting tired of all these allegations. She doesn’t need this drama and is ready to move on.” 
 
 While reps for Lopez declined to comment last night, the second source sniffed, “The focus should be on her work for the foundation and the concert, not Casper Smart.” 
 
 The latest Smart uproar comes after transgender bikini model Sofie Vissa tried to shop a story claiming that she shared intimate Instagram messages with Lopez’s boyfriend, claiming to have screenshots of their alleged chats as well as “naked images of Casper Smart,” according to thedirty.com editor Nik Richie, who first exposed the Anthony Weiner sexting scandal. 
 
 Smart, who has since become a choreographer and creative director, first met Lopez when he was a backup dancer. His representatives did not respond to our e-mails for comment Monday night. 

 Jennifer Lopez isn’t taking any chances when it comes to details about her personal life, so she had boyfriend, Casper Smart, sign a legal document agreeing to never spill secrets about their relationship to the media, RadarOnline.com is exclusively reporting. 
 
 Married three times, Lopez is “very savvy when it comes to business, but her love life is always filled with tons of drama,” a source said. Her manager, Benny Medina, reportedly told her to draw up the document in order to protect her brand. Smart had only been dating Lopez for a few weeks when she sprung the legal document, known as a non-disclosure agreement, on the choreographer. 
 
 The document states that Smart is never allowed to discuss his relationship – business or personal – with Lopez to the media, unless she has given prior written approval. He had no problem signing it, which made her very confident that she was at least dating a good guy. 
 
 There are no financials in the agreement, but it does say that if Smart breaches the agreement, she has the right to sue him and recover any gifts she had given to him during the course of the relationship. If Smart follows the rules, “he is allowed to keep all gifts,” the insider told RadarOnline.com. 
 
 Radar broke the story that the American Idol judge, 44, has fled to her native New York City without constant companion Smart, 27, and sources reveal that the nearly three-year relationship is essentially kaput. 
 
 “Jennifer has been embarrassed by him yet again,” a friend tells Radar of Smart, who has denied straying on the superstar. “He was not invited to accompany her to New York.” 
 
 PHOTOS: Jennifer Lopez Star Style Evolution 
 
 After another transsexual model allegedly has exposed her sexy Instagram chats with Smart, a fed-up Lopez finally has had enough. 
 
 “Things started to go downhill when Casper was fired as Jennifer’s creative director after the show in Dubai,” the pal explains. “He was basically demoted to her cabana boy.” 
 
 Now, mother-of-two Lopez is holed up in a Manhattan apartment, the source adds, diligently cutting Smart from her future travel plans. 
 
 PHOTOS: Busted… BIG TIME! 12 Hollywood Stars Caught On Camera Cheating! 
 
 “Casper was told he’s not going to Brazil for the World Cup,” the friend reveals of the international men’s soccer tournament, beginning June 12. (Lopez released the Cup’s official song, “We Are One (Ole Ola)” with rapper Pitbull in May.) “Soccer is his favorite sport, so it must really suck for him.” 
 
 Nik Richie’s TheDirty originally reported allegations last week that Smart was having an affair with curvaceous transsexual model Sofie Vissa. 
 
 Meanwhile, Lopez’s advisers are “urging her to just end the relationship with Casper. All of these headlines about dating transsexuals is just tacky, and detracting from all of the great things going on in her life. Casper is just bringing her down,” the insider added.
– Nothing says romance like ... a non-disclosure agreement? Apparently so for Jennifer Lopez, who, sources say, made boyfriend Casper Smart sign one after just a few weeks of dating. After three marriages, J.Lo is "very savvy when it comes to business, but her love life is always filled with tons of drama," one source explains to Radar. So her manager, Benny Medina, suggested she draw up the document, which prohibits Smart from spilling the juicy details of their relationship publicly. The NDA stipulates that if Smart breaches it without Lopez's prior written permission, she can sue him and take back any gifts she gave him. (He also had to sign an NDA before they started dating, since he worked for her as a choreographer.) But after almost three years together, things don't appear to be going too well for J.Lo and Smart; she's in New York City without him, and sources say they're on the verge of a break-up. Why? Well, according to Page Six, rumors are swirling that Smart has been secretly sexting transsexual models, and Lopez "doesn't need this drama and is ready to move on," as one source puts it.