1. they will not notice, but if they did...
2. they will not care, however
3. you are a sweetie for even thinking twice about it 🙂
Give the bag to your brother and everything will be ok. This is a promo, and they have plenty of them. If you were hoarding them or selling them, then that's one thing. If they did know about this right now, they would not even blink. They would wonder why you were so worried, and probably giggle.