我说不离不弃纯属童言无忌
[wŏ shuō bù lí bù qì chún shŭ tóng yán wú jì]
'我说不离不弃纯属童言无忌' translates to 'When I say 'I will never leave or abandon you,' it's all childlike innocence.’ It indicates the pledge was made naively, without consideration of long-term commitments, similar to saying something carelessly as a child would do, disregarding serious consequences.