Actually, as "opposite-sex buddies", there must be a limit to everything. Although the relationship is very good and you can be very casual, after all, you are not lovers. You may not mind, but you will have boyfriends and girlfriends in the future. Don't they mind?
You are not lovers and have a good relationship, but there are many gifts suitable for boys that are not suitable for you. As the saying goes, the sender is unintentional, but the sender is intentional. It is inevitable that others will say something, and even your buddy will think about it.
As for what to give, you can give a sunshine jar. The sunshine jar is suitable for anyone. The meaning of the gift is different for different people. It can be said to be a polyhedron. It can be very ordinary but also very warm. It looks like a decoration, but it is also very practical. For example, it can be used as a night light and is much better than those switches. The sunshine jar is light-controlled. When it is dark or the room is dark, it slowly releases light and warmth. When the light is strong, it will slowly turn off the light source automatically (cough cough, in fact, there is a switch on it, and it can only be turned on). For boys, it is most suitable to choose constellations or no patterns.
Of course, if you have such a good relationship, sometimes you don't need a gift. Going out for a drink with him on his birthday can be considered a very good gift. (Girls can drink but should drink less). Gifts are not just material things that can be bought with money. The best gifts are often not related to money or material things.