Hey!
Does the other part in the conversation see the "last seen" for me when i only check his/her response in the notification bar without actually opening up the WhatsApp app?
Sometimes i check the answer in the notification bar (when it's a short one), and don't want others to see if i have checked their reply. So i wondering if you check just with through notification bar it works? The phone in question is Google Nexus 5 on Android 4.4.4