My poor husband, you girls are too sweet. I walked in the door with Ollie one evening and said "Here's our new baby boy...his name is Oliver Wallington. Isn't he cute!!!???" And then quickly added, "And by the way, you need to watch him because I"m on my way out the door to go get his sister and her name will be Olivia Beatrice....see you in about 30 mins!" And walked right on out the door.
If you don't give them the opportunity to have an opinion, you don't have to worry about what it might be!!!
Or you can do what I do and tell him you'll let him know what he thinks about it once you've decided.