I love when girl teases. That's so hot and horny, makes me hard in a moment!
Your wife is very sexy and does her business very good) don't let her stop, lol
#4 for sure.
But I think it's better to show her face to her friend. Photo with face for you (like an example), so she is not shy with you but by mistake it was sent to him.
I will be really suprised to receive such "mistake" and I will "trust" it.