Can my husband's probation officer search my things. For example, my drawer that has my underwear etc.

Of course he can, or every probationer would hide stuff they can be violated for in their wife's underwear drawer.

If that is where the probationer lives, yes, they are allowed to search anywhere in the house, where they live.

That is the terms of probation that he has agreed to, and by you allowing him to live there, or you living with him, you have accepted this.

" I bet if I put that El Dopo in her 42DD, they would never even look there, lots of room to hide it".