All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
Joking about religious matters does not necessarily mean apostasy; it may be allowable in some situations. For instance, it was narrated that an old woman came to the Prophet, sallallaahu ʻalayhi wa sallam, and said, “O Messenger of Allah, supplicate Allah to admit me into Paradise.” He replied, “O Mother of so-and-so, an old woman does not enter Paradise.” She left while crying, so he said, “Tell her that she will not enter Paradise as an old woman.” [At-Tabaraani - Al-Albaani graded it saheeh (sound)]
The Prophet, sallallaahu ʻalayhi wa sallam, used to joke with his Companions, but he would only say the truth, as we explained in fatwa 82375. A Muslim should accustom his tongue to telling the truth all the time.
The two statements mentioned in the question do not seem to involve Shariah violations to us as long as the addressed person and the listener understand that they are meant as a joke and not to take the mentioned sins lightly (stealing and listening to music).
Allah knows best.