My sister and I have always had a hilarious time with something like that. We always seem to know what the other is going to say. I would start signing for her to a deaf/hh person (she doesn't know as much vocabulary as I do) before she even started speaking or she would start speaking for me to a hearing person (as she is hearing also) before I even started signing. We would be right what the other wanted to say, even for random topics or off-topic remarks, and we didn't discuss it beforehand. We also teasingly yelled at each other for reading the other's mind and for one of us not giving the other the time to start speaking/signing before the one of us "interpreted". Or we'll say/sign something at the same time
(we did that ALL the time) and say "jink".
A hilaroius example in high school. We were studying history for the final exam (so there was A LOT to go over), but we wanted to do well. We didn't want to make it easy for the other by giving out information that might "give it away" or by going in an order, so we jumped around. We got to the point where we could accurately answer the question of "Who did what, when, where, and why? We cracked up after that.