My girlfriends mom???

my girlfriend and came home from college and every time she's came hone I've been out of town so when she came home I got to see her and we had sex and her mom walked in and wasn't disturbed before I left she asked me to come in her room and raped me and said she was going to show me to have amazing sex and sometimes she calls me over and says she need my sex and so does her daughter so Ive been at there house every other night having sex with them! is it just me or are they crazy