Jealously

She jealously guarded her husband and didn't let him talk to anybody.

Magicians jealously guard their secrets.

Then too the sheep began to bleat, while the lambs frisked on the sward, or stooped under their mothers to suck. And the he-goats contended for their mates, jealously guarding the one they selected from the approaches of any rival.

Stealing noiselessly into her sleeping father’s chamber she detached from his girdle the key he guarded so jealously and opened the gate.

Jealously can destroy people's lives.

Gabor was burning with anger and jealously.

"[…] I hope you find nothing risible in my complaisance?" replied his companion, something jealously.

Ah! my brother, we do well to watch our birthright jealously; the least invasion on the meanest peasant, the slightest encroachment of the powerful, are not matters to be neglected—such are the first steps of tyranny.

Very many thousand times above Dudley Sowerby, Nataly ranked Dartrey Fenellan; and still she looked at him, where he sat beside Nesta, ungenially, critical of the very features, jealously in the interests of Dudley; and recollecting, too, that she had once prayed for one exactly resembling Dartrey Fenellan to be her Nesta's husband.

Another friend was present while I was there, veteran criminal defense attorney William J. Brennan, jealously guarding an SUV full of memorabilia he’d purchased, including a Rizzo fedora and walking stick, the former of which he told me he hoped Rizzo was wearing during the famous “crumb bum” exchange with television reporter Stan Bohrman.