What to do in times like this

Ok so im with this girl who is 37, im 34 we have been togather for about 8 months. Now i treat her with respect and lots of love no matter the circumstances, everything is good for us except that she has a son that is 21 and does not like me for nothing. He dont even know me nor does he even want to. This is her babyboy of four boys in which the other boys are with the dad who has remarried, but for some unknown reason her son trys to keep everybody away from his mom. Now i understand the whole protection thing but come on his mom has not been happier. I have gave him no reason to not like me. This is the wired part i have to get snuck in to her house and i cant talk when im there because of her son, i just dont know what to do.

he does not trust you with his mum,okay dont force it let time pass,he will get used to you in time

You need to be straight up about being there. Stop sneaking around. That does not build trust. If you are straight up about it, he will get used to it. Also I think your GF is older than 37, unless she started having babies at 12!