I fear for my loved one.

It has been a problem that has been growing bigger in my family lately. My father has become a teenager again, hanging out with his friends almost everyday till late hours of the days, my mother, as loving as she is, suffers because of this, because she is a housewife, she tells me that she sometimes feels depressed because she feels alone, I dont understand why my father fails to see what my mother is going through, I want to confront him and tell him, but my mother says I shouldn't. I dont want my mom to get depressed.

That's hard to have to watch. I would tell your father how watching it is affecting you (your mother's staying at home and not having interests of her own is your mother's problem and your father's hanging with friends is his choice) but not tell him what he should do. Something like, "I feel sad that Mom is at home alone so much."

well my mom is a strong person, but i seems to me that she makes herself weak in the presence of my father. that makes me sad

Sounds like a mid-life crisis or mid-life episode. Getting old is really tough.