I'm having trouble with the Medela Soft Cup nipple. Today we tried usi…

I'm having trouble with the Medela Soft Cup nipple. Today we tried using it for the first time, but the baby is refusing to drink from it, even crying hysterically. We have the same problem with a regular plastic nipple. Should I be forcing him to drink until he gets used to it or is this not how it should be? We need a feeding method where the baby doesn't refuse the breast and relatives can feed him while I am away. Please write concisely, not "breastfeed, don't complicate things" as I really need a solution that allows breastfeeding while also allowing others to feed him when I am not available.