Strait doesn't let his sex-symbol status preclude playing a cuckold in ''She Told Me So,'' an obscure old George Jones LP track that appears on his latest disc, It Just Comes Natural: ''Each night she thanks God for the day she found me/Why, when she came home this morning, she told me so.'' Ouch! Just as grand, in a sad-sack way, is his current No. 1 country single, ''Give It Away,'' where he's so disgusting to his departing ex, she doesn't even want half their joint assets. Strait only sometimes gets the girl as in his cover of Bruce Robison's besotted ''Wrapped'' but he always gets the hit.