Like others have written, it would depend on the relationship. To me, an ATF is one that you see frequently as in maybe several times a month, or more, so I don't see how they could gain/lose weight without my knowing it. However, I did have an ATF for over 6 years and she did go through some weight gains/losses but I knew since I saw her frequently. Did I stop because of that? Nope... the only reason I stopped seeing her was because she moved out of Houston but that was more than a few years ago.
Reese, 37" hips are just fine for a lot of guys and I think you are just right.