Why is he mad because i don't like him teasing me? i tapped my nephews head on the table?

Yesterday i went out with my guy friend it was supposed to be just me and him until my mom asked my bf if he can ride my sister to her Dr. appointment who just gave birth to my nephew almost a month ago.So he agreed to take her she went to her appointment and we had the baby with us til she was out. We went like a few doors down to this pizza place where we went in and sat down to eat the baby was sleep at this time but started fussing now mind you he is a father of a ten year old and i am a mother of no one that would make him the experienced one.While the baby was fussing he said to me get the baby bottle out and feed him.He then replies i knew i would be the one doing all the work he was like you couldn't even tell if the baby was hungry. so i was like okay he was like im colder than you bc he knew that He asked me to burp the baby so we took him out the car seat and i started patting him on his back now when i started patting him the baby was turned towards my bf the table in front of his head he was sitting on my lap and i did not place him over my shoulder to burp him i just set him n my lap so my bf said i tapped his head on the table while i was patting him i did not feel him tap the table nor did he cry and i was like no i didn't he said im sitting right here watching u so he said why don't you place him over your shoulder and as i was about too he just took over and was like give him to me in i can do it attitude and started joking with me say in im a baby abuser and when your sister come she is going to beat you up now he was joking but i didn't like that he was saying that and it was er-king me and he knew it and kept doing it so when my sister came i told her what happened but he was exaggerating the situation making it seem more in a sarcastic way. So she goes along with it and then they wouldn't leave it alone.On the way home he was like still at it and at this time im getting pissed off so i go home go to sleep wake up he calls me and wants to still bring the issue up he was like did you tell your mom and your gonna be 45 and people are gonna still be talking bout that so i got quiet on the phone and chose not to say anything so he was like now you ignoring me then he asked me you know they gone be talking about you right i was like i guess cause didn't want to talk about it no more then he was like i have a Sh*tty attitude and i need to have a sense of humor hangs up on me well he made feel bad bc i didn't have children never dealt with infants so i go off what people show me and then he s more experienced than i am but teases me about the whole incident practically all day gets mad at me hang the phone up im my face and calls me a soft *** B*tch bc i was the one who did that dumb sh*t and cant take the teasing am i overreacting is some wrong with me for not wanting to laugh no more please be honest with y'all how would you react