I have had my iphone 5s (still have version 7.1.1) for three years now and never have encountered such a problem until recently.
When I plug my earphones, it works well depending on whether i want to facetime or play music but lately, it frequently stops, skips, pauses songs or activate Siri on its own accord. It even ends my facetime calls while i'm talking, so i have to call back every time (I can call back for more than 7-10 times).
Can someone help me???
PS: it never does this when its not connected to my headphones