Should i have to buy a stupid vibrator?

Im currently living with a girlfriend. We have been on and off and she moved out of our apartment but has now moved back. Our was in a real slump for a while but has since picked up yet she is ALWAYS asking me to buy her a vibrator for fore play etc. Is this normal i mean she says shes just scared to buy it which i could see but shoud I have to buy the thing? I feel like that looks even worse!