expression, ichidan verb
be suspected without cause; be falsely accused
Idiomatic expression literally meaning 'to have one's non-painful belly examined', used when someone is groundlessly suspected or questioned about something they haven't done.
彼は何もしていないのに、痛くもない腹を探られるような質問をされた。
Even though he had done nothing, he was asked questions that felt like being suspected without cause.
上司に痛くもない腹を探られて、とても不快だった。
I was very uncomfortable when my boss suspected me without any reason.