If he bothers you again tell his wife. Ask her to please have a talk with her husband about his being "too friendly".
If he comes up behind you and starts to get too friendly, jab him hard with your elbow or stomp backwards with your foot on one of his, and say, "I'm sorry, I didn't see you." Keep a clip board or something else with an edge handy and jab it into his stomach if he comes at you from in front or the sides, and say "Back off, you are a married man!"
You do also need to look for a job somewhere else, though, because this is not a healthy situation, and creeps like him don't suddenly get cured of being jerks. Do some networking with friends and relatives to find out who might be hiring.
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If a man does not keep pace with his companions, perhaps it is because he hears a different drummer.
Let him step to the music which he hears, however measured, or far away.--Henry David Thoreau