Onomatopoeic expressions / imitative word / mimetic word

A; He looks animated recently. He looks very excited recently. 
彼最近 ' 生き生き ' してるね。
B: Oh. Didn't you know he has engaged himself to Masako last week? Oh, didn't you know he and Masako got engaged last week?
　あれ？　彼が先週正子と婚約したの、キミ知らなかったんだ？
A: No wonder he head straight somewhere joyously as soon as he finished the company. No wonder he headed straight home after work.
　どうりで、会社が終えるとすぐ何処かへいそいそと向かうわけだ。
B: Who doesn't know。Both are now lovey-dovey. Everyone knows because they are both very affectionate.
　あたりまえさ。　二人ともいま ' アツアツ ' なんだ。