This question already has an answer here:
My girlfriend once had a friend pop round her house and he brought his friend with him (both male). I replied "txt me when they're gone and I will come round," as it was early days in our relationship and I am little jealous and we had a minor falling out over something.
She sent me a txt saying "they have gone" and a couple of unrelated things. At the end of the txt she said "I have butterflies."
I see the expression having butterflies to mean you fancy someone or have a crush on them. I wouldn't want her to have a crush on her other friends: is that what "having butterflies" means?