answer: #Person1# invites #Person2# for the picnic and dress party tomorrow, but #Person2# isn't available.
documents: #Person1#: Would you care to join for the picnic tomorrow?
  #Person2#: Much to my regret, I'll have to meet my girlfriend at the airport then.
  #Person1#: We'd like to invite you for our dress party tomorrow evening, are you free?
  #Person2#: Much as we'd like to, but we've booked up already for that time.
  #Person1#: What a pity! You can't join us.
  #Person2#: So sorry. Next time we'll go, thanks anyway.