Am i missing something. Wtf ! What really going on !

My friend. My cuz by marriage live in his own trailer on my property. .. Which is way ok .. So i kinda know or have seen his actions to things that happen. Not uncommon correct .. So i owed him 30 dollars. This is odd my dad lives with me ok. So one day he came in told my dad he was going to a job down hill. ... First weird thing is hes never expressed to my dad hes doing and why . ok. So i came home dad said have you talked to ... And told me. What was said .. Ok . knowing in the past my cuz . has said im going to work. And 30min later hes still here. And because he didnt have gas... So me owing him assumed since his truck was stilll here he must not have gas because owing him wouldnt stop him from work. .. Ok so i had 20 dollars and said i can get you gas because thats all money i had at moment. .. He freaks out saying i took his truck. And i took his frind home. On and on. Whats really going on or am i wrong for assuming. Whats his problem. Or did i miss something here?