My fiance had his mom claim him behind my back without talking to me first so I was pretty annoyed but nothing I could now. We would've gotten more back if he would've waited and let me done them . Anyways tonight I filed mine and got to the end of the tax prep where I got a warning that someone already claimed me as a dependant ??? We lived with his mom 3 months last year while we found a place paid half her rent drove her everywhere and paid the electric and groceries so all she paid was half the rent and water. But she's the only one who could even have the information you would need to claim someone as she did "find " my wallet one day which as my ID and SS card. I'm pretty sure she would've done it and I wouldn't be surprised if he was in on it too since he was acting weird when I asked him why he went behind my back when we already had an agreement. I'm worried I'll get audited now I've never had a tax issue before. Any advice ?