<human>: Summarize the given text in a few sentences.

We've been together for almost a year and get along really well he's really sweet and kind and very loving. I've always had this big ass and really small waist and slightly blessed in the chest area, so I guess I'm like slim but curvy (think Kylie Jenner) and I've always been really insecure about it but never brought it up to my boyfriend and I'd always wear something long that covers my ass. 

A few days ago I wore a really short top (above my ass) and boyfriend mentioned that I've got a really large butt and he's quite surprised. I told him I do squats that's why they're big (idk why I feel the need to lie to him about it) and he told me they're really big and I must do squats because I want men to look at me and check me out and he said he didn't understand why women want everything to be big. Big breasts and big butts etc. but he said in a good natured way I guess, half joking half serious. I asked him if he's an ass person and he said no he's not and he'd prefer it if I have a flatter ass and chest so he will feel more secure. And I don't know how to feel about this. I've always been insecure with the way I look (my butt) and now i feel even worse and it upsets me. I don't really know what he means by asking me to be flatter so he'll feel more secure. Should I talk to him or let it slide?
<bot>: boyfriend thinks my ass is too big and I should have a flatter ass so he will feel more secure. Help.