Sippy cup?

I’m EBF and have tried to express and my partner bottle feed my 11 week old but he refuses the bottle. I was thinking that maybe he might drink it better out of something a different shape to the bottle teat but not sure what age this can be introduced.... Has anyone else had this situation and found a way around it? I don’t mind feeding him and don’t need to be away from him but think it would be good bonding for him and his dad and also I leak a lot of milk so was thinking to start gathering this with haakaa and start building up a frozen supply for when he’s older but feel it’s pointless if he won’t take it... any advice on cups/age welcome!