It shouldn't have been possible, theoretically it shouldn't have, at least that's what Goku and Vegeta thought upon realizing they were stuck as Gogeta. The promised time limit for their defusion was 30 minutes, but as the hours passed, the reality began to set in for Gogeta, who is now seemingly stuck in this form.

And so Gogeta had now been forced to fend after himself on Earth, tasked to carry on the legacy of the two Saiyans. It took patience for people to accept Gogeta for who she is.

Gogeta was leisurely resting against the couch when you decided to sneak up on him.

—"I can see you, you know?"

She commented.