sms - In a group/mass text message from an iphone to other phones, who sees my reply to the group msg from my android?

If an iphone user sends me a group/mass text message on my android and I text back and hit reply (not reply-all) not realizing that it is a group/mass text, who sees my reply? Just the original sender of the group msg(an iphone user) or everyone that was included in the group/mass text? I use the stock text app on my android(Verizon Samsung Droid Charge) and there is no reply-all button in my text app. when I reply to text messages. I only received one text that was a reply to the original group/mass text, but received nothing else from anyone in the group. The iphone user that sent the original group/mass text says that she is the only one that probably received my reply. Not realizing that it was a group/mass text. I REALLY want to know if anyone else besides the original sender saw my reply. When I received the text there was no indication(on my android) that it was a group/mass text.

Thanks so much!