My parents and guys.?

my parents are pretty stricht and i have a boyfriend. when i go to parties there are guys there and my parents are fine with it. like one time i went to my friend jess's house and theyre were some of my guy friends walking down the street and my mom saw us with them and she didnt care. but then before i was going out with my bf my friend sierra is his next door neighbor and i went to her house and he was walking to go get his sister from school and my mom goes that your boyfriend im like no shes like then why is he coming over and im like cuz his little sister is right there. now that i am going out with him im not even allowed to go over her house anymore. and like ive never had a party with guys cuz im afraid what my parents willl say. it seems like they wont let me be friends with guys. like there is one kid i hate!!!! and i have to be best buddies with him cuz of our parents. how do i convince them i have guy friends?and let them come over sometime possibly...?with other friends to