Guys what would you do if you were him?

a guy at work tends to be flirtacious with people at work and i'm one of them ,he also jokes a lot, he is engaged so i dont know why he flirts ,i ignore him, i went on vacation and came back and he said" i thought you had gotten hit by a bus" (since i was gone a while) i said i was in myrtle beach and he said 'wishful thinking" and then i had enough of his tattling when he decided to snitch on me to my best friend b/c i said she hadn't clean something right, (we work together) and he was laughing about it and i looked at him straight in the eye and told him to go f*** himself and he stopped laughing and looking away he said you can't cuss and looking at him i said you dont know me at all and he said you're right , i dont, still looking away -he was nice the rest of the day, the next day he told me this table had gotten sat so i wouldn't sit it in a low voice and he couldn't even look at me..why?