MySQL Slave database size >> Master Database
From the details, it looks like the 'massive' difference is ~70MB in the dataplay schema. You can adjust your query to find out exactly which tables are different.

Two potential reasons for this difference is:


Schema difference on the master vs slave. Does the slave have utf8 instead of latin1 on a column or three? Does the slave have additional indexes? You can compare the schema by running a mysqldump of just the schema (--no-data option) and then diff'ing the results.
The slave has actual different data. Do you have session-only data that the application stores and won't matter? If no, you can use pt-table-checksum to find rows that are actually different. Then you need to dig into why they are different and fix that issue before reseeding the passive master or using pt-table-sync to resolve the differences.