I've been datin my boyfriend for 4 week now he is 17 I'm 16 he is a really nice guy but the only problem he stole off my sis and was abusive to my mum but that was sorted out got money back but he never allowed in house again but I go up to his but I really like him and don't want to split up with him as I love him but didn't like what he did I also gave him a bracelet and forgot that my nan gave me it before she died he now saying he lost it my mum said I got to break up with him the longer I'm with him the longer she won't accept him and if I have kids in future she don't want to know him and will disown me but I don't really want to break up with him and don't want to go out with him behind her back because how would I see him I don't know what to do I just want everything to calm down so I can be happy with him my mum thinks I'm puttin him in front of her but I'm not we are deeply in love with each other I know he don't wrong but he has been disciplined for that I don't know what to do help please?

You have only been dating this guy 4 weeks. You can't be that much in love. I that short period he has shown you that he is a thief and is disrespectful. He lost something precious you gave him so he has no respect for things.
Is he your first boyfriend or something?
Don't mess up things with your family over a 4 week relationship with a creep.