请问“礼尚往来”用英语怎么翻译，谢谢！！！

礼尚往来:
courtesy demands reciprocity

Friendships cannot stand always on one side.
礼尚往来。

We gave the Smiths a bottle of gin last Christmas, so this year they gave us a bottle of Scotch to even things up a bit.
去年圣诞节我们送给史密斯家一瓶杜松子酒，今年他们便给我们送了一瓶苏格兰威士忌酒，以使礼尚往来。

礼尚往来
①Courtesy demands reciprocity
②Etiquette requires reciprocity

Friendship can't stand always on one side.

courtesy demands reciprocity