<>I imagine that the new neighbor was being polite when he heard your older neighbor call you fat.  He was empathetic and sympathetic to the name calling.  Now the question is, what made him change?  Why did he too, revert to calling you fat?  The nerve of some of these people whom crosses our paths.  Have they no disregard for how one such as you may feel.  Well, maybe in a one-on-one evironment with you, he is totally honest, and he realizes that you are not fat at all but just pleasingly plump, (if you don't mind me saying so).  On the other hand, I'm sure you've heard the old saying, "birds of a feather, flock together."  Well, maybe in a more-than-one person environment, your new neighbor  is a follower and just didn't want his new friends to know that you and him have spoken on  good terms and he may like you still, but revert to the name calling because his buddy is doing it.  He also may have more of a neighborly tie with the older neighbor you know--same gender, same activities such as drinking beer, if done at all,  and hanging out watching the ladies, as well as name calling.  Also maybe the older neighbor may have told the new neighbor something negative about you which makes your new neighbor now seem so unfriendly.  In any case, your new neighbor is as I've stated, a follower and not a leader.  I would suggest that you do  not say anything to him anymore until he speaks to you and I'm sure this could be one day very soon.  Just acknowledge his greeting when he gives it and take it one day at a time.  My guess is once he see that you are a sensitive person, (as you wrote us to question this matter, apparently it hurt your feelings) he may find you to be one of the better neighbors in your community and may become your best friend.  He may really like you and called you fat to keep the other guy away.  Either expect an apology from him, no communications at all or the same act of name calling. You will need to decide how much you will or can tolerate. If the name calling continues, do not accept it.  Stand your ground and tell him how you feel. Be well and stay safe.