IMO he is right to wait at least Hikari leaves to avoid actively him and wait for a chance to see her in public. If Hikari is bothering so much for avoid Yuu, is because she knows he is really able to encounter her in a public space and convince her to talk at least, preferably, again, in a public space or his house.
I mean, as a victim of a violent agression from Hikari, Yuu is definitely making the right thing to avoid enter in her house and even more if Hikari parents are not there to protect him.
A boy doesn´t want victim of violence again after being mistreated twice by the two girls of his life? "Meh, is because he is spineless, secure". So, my mysandria accusations are valid.
The poor boy was already very uncomfortable while Haru was lecturing him, he seemed a little kid lectured by his mother, and all this in a public site where he can have at least the minimum security Haru cannot agrede him as Yami and Hikari did it before.
He is in his perfect right to avoid CONFRONTATION and ask Hikari for a civilizated CONVERSATION as the mature teenagers they supposely who are, instead have to endure more insults and physical aggresions from her. Even if he is still uncomfortable talking about this, but he is disposed to respond all the Hikari questions because he thinks, and he is right, is his duty as friend and love interest who confessed to her.
So, is very logical Yuu is trying to look Hikari outside her house and/or waiting for the visit she promised to Yuu mom.