Im so scared help me what do you think is going on?

Ok well, my dad text messages a lot. I don't know to who he is or what he's saying, but 1 day he left his cell phone in the soda spot in the car and I saw a few words (they were in Czech, my language) and I noticed a word that said "milacek" which means "dear" or "lover." Anyway, today at about 7 pm, my dad said he was going to the garage, but I thought about it and I said to myself, he's lying. So I looked out my kitchen window (we live in an apartment) he threw away some trash. Then he looked at the the balcony, and was going somewhere else. He was going to my brother's I thought. I said something bad must be going on. But I went back to my computer. Then, I decided I must see whats going on. So I left my apartment, while my mom was sleeping, and as I was going down the stairs, I heard some voices. It was my brother's wife and my dad talking about something. I was scared to get close because I didn't him to spot me. So I stayed a little far enough to hear a few words.