<human>: Can you condense the text into three sentences or less?

Basically when she says I love you, she does this odd thing where she raises the pitch of her voice really high, to seem gentle I guess, and ends up sounding mentally challenged. I'm not trying to be offensive but for the purpose of description that is what she sounds like, it comes out like "I laahie". Anyway, I love her back but sometimes when she says it some of the laugh escapes and I have to turn it into a "I just can't believe how cute/beautiful you are and you make me smile" or something like that but I think she will catch on soon if I don't get it together. Should I just tell her?
<bot>: Girlfriend sounds ridiculous when she says I love you and I have a hard time controlling my laughs. What do I do?