I need some MARRIAGE advice!!?

Hi, i've been married for 4 months and we have been having so much trouble in the relationship. Well 4 days b4 i we got married i went tru his cell and found some flurtations text msgs that he sent to a female. I confronted him and he got mad and denied it, ok we worked it out.Then like a month after i checked his cell and found nude pics of a girl he works with, i confronted he denied it and promised he wasnt gonna do it againg, then a month after found new pics of the same female and same thing he said to me FORGIME ME WONT HAPPEN AGAIN.the third time i checked his cell nothing i checked his email and there they where..i left him for few days then i went back with him.BUT NOW he did d same thing i was really mad and now i dont know what to do i want to leave him but i cant decide? is it wrong to have nude pictures of a co-worker in your cell and in your emails when ur married? is that cheating? would he change? please i need some advice..