。
Don't butt into my life.
Literal
I [of-の] life [in-に] mouth [object-を] don't-put [give-くれ].
口を出す ('to butt in, to meddle,' literally 'to put one's mouth in/into') is a fixed idiom for unwanted interference in conversations or decisions. The negative command ~ないでくれ ('don't, for me') is assertive but asks rather than orders. 人生 ('life') marked with に as the target of the meddling.