Jealousy's roots are from love. I've never seen a stranger jealous of some random man kissing his random wife. Only people I've seen jealousy are those who's heart is involved in some way. Make the distinction between jealousy and envy.
jealousy
[ jel-uh-see ]
noun, plural jeal·ous·ies for 4.
jealous resentment against a rival, a person enjoying success or advantage, etc., or against another's success or advantage itself.
mental uneasiness from suspicion or fear of rivalry,
unfaithfulness <<<<
, etc., as in love or aims.
vigilance in maintaining or guarding something.
a jealous feeling, disposition, state, or mood.