Jessica Alba

my friend\’s girlfriend is jealous of me?

I have known my male friend about 3 years,and his girlfriend is my friend too,I like to spend my time with him,but not in special,I like him only friendly,I think he thinks the same about this issue,sometimes two of us are hangin out together but usually we are hanging out all together with our company,the last time I had to wake up early and my own house is far away from school,I had to stay at his home and I stayed,we had a good time and the next day I told her girlfriend that we were stayed at his house and I had to,she changed her behavior towards me,and I felt weird and a bit angry,how can she feel jealous about me,we are just friend not more than that,and what should I do?