Nudes: what's normal/too much

Ok so I've been snapchatting nudes with you friend and basically sending him body/ass/boob pics but he recently said he wanted to see my vag..anyone have a reason for this besides getting turned on? That doesn't really seem plausible to me and he was doing fine when I wasn't showing him  my lady bits. I don't get the appeal to him..we've never had sex or done anything sexual at all besides this and it's like long distance