According to TMZ, it was a combination of things. First up, the couple’s biggest issue was that Britney wanted more kids, and Jason did not. The couple argued about it frequently and couldn't compromise. That definitely seems like it could be a deal breaker.
Another struggle for the couple was about Jason feeling as if he were losing his individuality in Britney’s world. When he wanted to grow his business by taking on more clients, Britney was not having it.
The good news? The couple kept their money separate, and it looks like it’s going to be a hassle-free breakup.