Husband and instagram

So we were separated and since coming back together I found he dated a fitness model. Well be kept telling me how even with her looking that way he couldn't get over his wife and when I asked for him back he dumped her really quick. Well since I found that out I've been insecure since before the separation he's talked negatively about my body. I turned his phone on a few times recently and have seen it open to naked fitness women on instagram. Each TIME he denies it.