Could someone help me understand the this strange behavior (inside for details)

Depending on your age, puberty & hormones are big factors in the answer to “why” in the sudden change.

I wouldn’t rule out shenanigans so just in case, thank them for the compliments and tell them you think it’s your vow of abstinence that’s got you glowing.~

I know that in my high school there was a running bet about who could get a certain girl to “give it up” among some of the more disreputable males in our school. I would avoid these boys like the plague if I were you.
@Neizvestnaya‘s retort will work quite well if you are audacious enough to use it.

Guys are evil, they just are. They LOVE little bets and games such as @athenasgriffin mentions. Most of my friends in HS were guys and they did atrocious things! Guys like to see if they can pick the most quiet girl they know or maybe one they think is the ugliest or whatever and then they get a kick out of showering her with attention to see what starts telling people or what she starts to do in return. I’ve seen guys go as far as flirting horribly with a girl and each asking her out to a prom only make jokes about it at her expense for months.

You are probably just growing into your looks and body. Look critically at yourself in the mirror and see how you may have changed.

Then thank them!

My guess? There is a rumor going around about you.

Dependent upon your age, it may be you chaningstill;, becoming more of a woman than a girl. It may also be the boys around you, becoming more like men than boys.

It may even be that you’re just becoming more aware of these compliments than you were. Kind of like people noticing a particular car brand much more, once they own it themselves.

In any case… make sure that you feel good about yourself, so that you may just accept and enjoy compliments without starting to doubt yourself or your environment, and without being tempted into doing thing you don’t want to do.