What is going on here?

Feeling very strange and insecure about my body have recently found out my boyfriend has a habit of liking girls pictures on Facebook that are much much younger than myself I being 27 then being 19 or younger and it really really bothers me because I'm not sure how to approach it to him but I am very small breasted and very small framed and to me I wonder if he is taking my small image and perverting it for his own needs though I don't really match the age that he's interested in has someone ever heard of something like that happening