My boyfriend and I play red envelope games in a group. He lost. I started giving him 50 red envelopes, then 20 red envelopes, and finally gave him 27 yuan.

I don't think the key is whether he stole money or not. On the one hand, he may have his own ideas that this is a trivial matter, and he doesn't want you to know at all. On the other hand, it is insincere to steal money from you today. Who knows how many things are hidden from you, but how does your boyfriend usually treat you? You can't lose your temper because of a trivial matter.