The first is active voice, the second is passive voice.
You might use passive voice when you don't know who did something (I was mugged) or if you don't want to say (Your vase got broken), or it's not important to say (The surveys were carried out over a three year period).
In all other circumstances, active voice is better: it's more concise, easier to understand and, most importantly, says who is doing something.
The expression coming out of your mouth is fine if what was said is inappropriate or offensive. If what's said is quite proper but not expected from this particular person, from your lips might be better.
So, you could say any of these:
I didn’t expect such things coming out of your mouth.
I didn't expect such things from your lips.