Non-bf parent...and the bath to rescue
My wife carried our first, so my role in feeding was a bottle of her pumped milk. But hell if he was going to take it from me if there was boob available. Someone gave me the tip of trying with both of us in the bathtub, and it worked like a charm. Baby relaxes, parent naturally relaxes, and our perceptive babies are so attuned to us that they pick up on it right away and respond in kind.
Based on that positive experience, I've applied the Bath Solution anytime things start to go a little sideways. Clipping nails, de-escalating screaming (parents or kids alike!), eating a snack or a meal, getting more volume while pumping milk.