I Want To Tell My Girlfriend's Dad That Im Dating His Daughter

well we've been dating for nearly 5 months, 
and i felt that its time that her dad knows our relationship,
but she keeps avoiding the topic when i was talking to her about tat,  she said that she'll tell soon,  but she never did,
well i saw her father once or twice,  and he looks like the strict type, 
im a chinese,  and its our custom to introduce our gf/bf to their parents,  bring them to our house and bla3, 

i dont really mind if she can go out with me freely even if her father dont know me,
the problem is,  i felt that i have limited of time when we're dating,  like we have to get back at around 10:30 (the latest) so that her father wont get mad and got suspicious, 
and we cant go out for like 3 consecutive days coz her father doesnt like her daughter going out on weekdays,  i mean,  for gods sake shes 21,  isnt a gurl around that age supposed to be given a mature thought by her parents that shes an adult and not be tied by a rope by her dad, ?

i really feel that by telling her dad that we've dated, her father would give us more time together when we're dating,  and we cud go out easier,  without thinking that her dad will get angry or somthing, 

so guys,  wat about your opinion about my story, ? T_T

hey if you want to let him know
go ahead, ooh and good lUCK!!!!

well just tell the old man that u are dating his child

becos if he findout by hisself it wont be nice,

i think so