insouciant, unconcerned, casual, laid-back, chilled out, Blithe, comfortable, serene, relaxed, sedate, more...

attentive, engaged, interested, invested

blasé, indifferent, aloof, cool, casual, chill, relaxed, unconcerned, more...

without a care,   care free,   not taking serious,   not insistent,   acting casual,   not a care,   acting cool,   not queasy,   careless tone,   casual and uncaring