How hard would be for a grown man who is getting married and who is going to have his own house, to learn something about ownership of Bitcoin before he accepts it as a gift from you?

It's better to teach a man how to fish than to give him the fish, and in similar way it is better that you give him instructions manual for generating his own seed words, and learning the basics of Bitcoin, than he can send you his public address and receive BTC gift from you.

Alternative way would be that you generate private key send funds to that address and then send him private keys with instructions to sweep it and transfer to address that only he controls.

I think that best option for newbie is to buy him a hardware wallet that has all instructions, he will have a sense that he owns something physical with seed words on paper + device itself.