raincheck       
verb [ I or T ] (also rain check) uk/ˈreɪn.tʃek/ us/ˈreɪn.tʃek/
 (不能应邀时)请对方下次再邀
to tell someone that you cannot accept an invitation now, but would like to do so at a later time
  Mike asked Sally out but she rainchecked. 迈克约莎莉出去,但她说下次吧。 
 How many times will you keep rainchecking me? 你还要我再请多少次? 
 - More examples
 - The person who initiated the whole idea is the one who rainchecked!
 - I just rainchecked plans with Molly because I'm sunbathing.
 - Sorry if our meetings get rainchecked this month.