My boyfriend said the weather was bad and didn't go out on a date. In fact, the weather was not that bad, but it was raining coldly. I don't care at all.

Maybe he has other things to do and doesn't want to upset you. Or does he dislike going out on rainy days? Be optimistic in everything, don't always be suspicious. This is just a small matter, which may be normal for him. Think from his point of view! If it really doesn't work, go out on a sunny day. Maybe there will be more things to do.