Don't over think the response you may receive- I made this mistake.
When I told my guy, he was hesitant about the whole thing. Not hesitant like, "why would you waste the money?" or "this is foolish," but more so wondering about how safe it was and assuring he loved me no matter my size (that's easy to say when you're the beanpole!!).
I talked everything over with him, we watched a video on youtube of a procedure, and we researched any questions he had. After watching the video and learning more about it and realizing the surgery is not "traditional" WLS, he was 100% behind me.
Just last night, I was telling my boss (who is like a second mom to me) that I would be taking time off for a procedure. I did not tell her what procedure then because of embarrassment/shame for having to admit I am a failure. She was genuinely concerned and asked me to tell her when I was ready to. After sleeping on it, I decided to tell her the full truth. I wrote her an email early this AM explaining everything and a few hours later I got an email back filled with love, encouragement, and support. I was so scared of what she could have said that I looked past how she has always been supportive of anything I do. It also doesn't help that she is super skinny/gorgeous- she just turned 51 but looks like she's in her mid-30's
I guess my point is, tell the people who love you. I am sure you will be given a lot of love and support. If you're not, then they just don't understand and it's not worth your time to dwell on it.