backscratching
noun /ˈbækskrætʃɪŋ/
/ˈbækskrætʃɪŋ/
[uncountable] (informal, often disapproving)- the fact of giving somebody help in return for help that they have given you, often in connection with something that might be illegal
互开方便之门,互相利用(常指从事非法活动)