abuse?

my girlfriends 14yr old and i got into a argument when his mom was talking to him about his community service that he has not done.He refused to listen so i walked over to the chair he was sitting in and told him to knock it off and listen to your mother,well he ludged up at me so i sat down on him so he would'nt hurt himself or anyone else,i told him i would get up when he stopped and listened.No harm was brought to him,nor was i trying to hurt him,i just wanted him to listen to his mom about something i think is important.Well now his dad wants to press abuse charges on me and wants to fight my girlfriend for custody.What are our options?And with his dad going around lying about what happened could i get him for slander?Please we need to know what to do.I helped raise that kid since he was seven and this is the only time that something like this has happened.My girlfriend and i just want closer on this matter.Please help.Thank you,DAN

see your other post