lay it on with a trowel

To exaggerate, aggrandize, or overstate some emotional experience, response, or appeal, such as blame, praise, flattery, excuses, etc. Jim carries on as though flattering the boss will get him a promotion, so he's always laying it on with a trowel for her. OK, Bob, I think Mary understands the trouble she's in, no need to lay it on with a trowel.