My dad is cheating on mum

I have discovered that my dad is having several affairs behind my mum’s back and this is making me so sick of him. I’m not yet 18, but this is really getting to me and I feel that he is betraying my mother. My mother and younger sister travelled recently and since then he has just been on the loose. I have read some disturbing text messages on his phone and found pornographic stuff on his laptop. I know he loves mum, but I don’t know what to do about this situation. I think mum would be devastated if she got to know about this, while on the other side I think it is unfair to keep this from her. Please help me out of this mess.

{Jesse}