I have a girl who is way too young interested in me right now. It's actually rather shitty because she
seems mature, but I've made that mistake before thinking someone was "mature for their age" and it turns out they really weren't. (I guess all that really means is they aren't idiots, which isn't really good enough.)
She's 16~17, and I won't bother. I just feel shitty avoiding her entirely, but at the time I met her I had no idea she was that young and the moment I found out I got really uncomfortable.
I guess even when someone may seem mature there is still a large difference in what someone in their mid 20's (or older) will want out of the relationship and what the younger person is really ready for/wants.
Jam it back in, in the dark.