As West, I have an opening hand and I opened 1♥ - by the time it came back to me I am bidding over 3♣ and partner has bid ♦s.  I cannot show my ♠ with our system (not strong enough to bid above ♦ or ♥ and Dbl is penalties) so all I can do is support ♦ with my 3 card suit.  Partner now thinks my 5♥s are better than they are and correctly bids 4♥.  With a slightly better break we can make this but not tonight!  Better to Pass.....

Partner now opens and we cn have a more constructive auction.  I can now support patner and we ignore the dodgy ♥s and find the correct contract, if only I would pass......!