get someone’s real intention [true intention, true feelings]
bring out someone’s real intention [true intention, true feelings]
「本音」は文脈・ニュアンスにより、real intention, real feelings, true opinion等。
「引き出す」はget, bring out, pull out, draw out等
「相手から本音を引き出す」は
bring out the other person’s real intention 等