Not long before I met my current girlfriend I had a brief relationship with a woman who was a fair bit older than me, almost 14 years. It is amusing because she went on about almost being old enough to be my mum, and I had to point out that my mum was quite old when she had me, and that my own sister is 15 years older than me so strictly speaking she was just old enough to be my sister.
Ugh, that is the worst. I also like dating older women, but there is nothing like the immaturity of not being able to handle a boyfriend who is younger than you. And it seems to happen every time. They always seem to get hung up on that fact, instead of just ignoring it and having a good time.