I don't know if I should keep faking orgasm

Firstly when you masturbate alone can you get yourself to orgasm through fingering?
Maybe you could just guide him to the right spot where it feels good for you because if your faking it if is meters going to find your sweet spot as every woman is different.

I don't touch myself and I never have so I wouldn't know. But when he fingers me I feel like I have to pee and then I just push his hand away because I don't want to pee on his bed

The best way to find out what feels good is to explore your own body, most orgasms are achieved more through clitoral stimulation than actual internal stimulation but what your describing about the feeling you need to pee sounds like your are experiencing the start of female ejaculation or as you have probable seen others talk about squirting.
A couple little tips for you is to put a couple towels down on the bed first and to take a pee and empty your bladder first then just relax and let the feelings take over and I'm sure your enjoy it :-)