So< this boy cussed me out in church, He's a pastors kid

So me and my friends were looking for my cell during service, Someone said to find the Sr. pastor’s sons, I find them in the sound system. I tap Mark on the shoulder (17, 16 at the time) he says “Damn, what the hell Destine?” his brother (12yrs old) says “Found your phone b****?” I ask Mark “Did he just call me a b****?” he said “yes”
My mom comes in and asks “Did you just cuss out my daughter” Mark says “Fu** yes I did!” she slaps him, And makes him and his younger brother go into the church foyer

He said “ I know that’s what I love about you, I was watching you and I said ‘uh-oh, she mad’ and I know you don’t play, you bad” I ask “you were watching me?”
He says “”I always watch you” he was holding this girls hand at one point recently, And He gave me this sad pathetic look. 2 weeks later, he looks like how he did when his other GF broke up with him, I hear his friend talking and he says the girls name and adds ‘friend’ to it. Mark purposely stood next to me once, Even though his friends were in plain sight. He’s always staring at my lips, And trust me, I make sure I look presentable before I leave the house. So why is he so mean