Is it permissible to examine the father of my brother through رضاعة (nursing/fosterage) if the mother is the one who nursed him?

The father of the questioner's suckling brother (the one nursed by the questioner's mother) is a stranger to the questioner, and the questioner is neither his stepdaughter nor his suckling daughter. She falls under the general meaning of His Almighty's saying: "And lawful for you are [all others] beyond these" (An-Nisa: 24). Therefore, it is not permissible for the questioner to uncover her clothes in front of him; rather, he must be treated like any other stranger.