<human>: First, I'd like to say that I've had body image issues and low self esteem/self confidence my entire life.

A few minutes ago we were talking about working out. I recently started and he suggested I work on my glutes. I asked why. He said "it would be easier to fuck" so I asked him to elaborate and he said "I had to bend low to stick it in cause you weren't strong enough to stick it up (my ass) at times". 

Okay, so that really hurt me. I feel like he doesn't like the way I am right now.. Like I'm fat. I'm currently 5'2" and 132 lbs. I feel like he wants me to change because I'm not good enough for him. He says that's not what he means but just the fact that if I "maintained" it, it would be easier to have sex. 

He's trying to tell me he meant he wanted me to "maintain" strength and ability… Not for me to lose weight but I feel awful right now.

Can you summarize the given text in a few sentences?
<bot>: Boyfriend said I needed to "maintain" myself so it's "easier" to have sex. I'm upset, I don't know what to do and I don't know if I should be upset about this.