Office politics, suggestions, please. :)

I am in the accounting/finance department. I am seating in a room with another girl, American. We are like friends and pretty close to each other. We talk, joke, go lunch, take breaks and laugh together very often and get along very well.

However, our boss, who is seating the next room, often comes to our room, and talk to this girl right off her ear with a very very low voice, so every time I don't know what they are talking about. I don't want to know or say I don't care what they are talking about. The part that bothers me is they laugh laud after talking like that, and I feel uncomfortable immediately just because of that.

Am i being too sensitive? Should I just let them go or I need to talk to them about my feelings? Or say just joke about it, but how? Please give me some suggestions or tips. It's has been so long and I haven't said any anything b/c I wasn't sure if I should raise my voice just b/c of that.

Thank you very much for reading. Happy working!