I do not think you over reacted. First and foremost...if you did not work to earn these letters, you do not need to even touch these letters. Well I take that back...you can pass me my jacket...but don't hold on to it too long LOL.
Secondly...if I come to your house...I don't care if it's a dirty towel, a sock, a bathrobe, a piece of paper, common sense tells you not to sit there or to move it before you sit there.
Thirdly...you just don't do that. My roommate is in DST and PBL...I dont even drink out of her cups with her letters on it. I don't care if that is the last clean cup in the house and we don't have any more dish detergent to wash another glass...I will go thirsty before I put my lips on some one else's letters...

Whhhhhhhhhhhhhhhew I feel like I vented...
Rubbing ears Woosa