Grinning from ear to ear. A smerk like you got away with something. Feverish grin with wide open mouth with or without teeth showing. "She smiled like a horse after being complimented by the younger man".
Smiling like a horse "She smiled like a horse after being complimented by the younger man".
Extremely uncomfortable, awkward, or revolting. Derived from trying to say "soothsayer" and being unable to pronounce the very difficult "th" sound. The state of trying to relate but failing and grossing everyone out.
The way he shook my hand was so soof-like, I felt the need to immediately sanitize my body.