[Flying Dagger]

Spoiler:

There is a little more before the those two lines:
Ebina:
"I really really like my current self and the people around me. Having been like this for a very long time, losing it is really regretful..... I like the current state I am in, as well as people around me.
"Therefore, I hate myself."


That is why, everyone is a liar.
But I am the biggest liar of all.


//**
What I think:
Ebina likes the stability of the present, but she also hate herself for the lack of courage of a change. This may imply deep down she may actually want to accept the confession but is just afraid of the effects it may bring to circle she is in: what will people think? React? What if things do not work out?
Tobe is an attractive target among the girls: so by accepting his confession she may damage her relationship with other girls.

So I guess, in a way Hachiman's solution is not a solution but just something to buy time. He may have to come back and fix this (Tobe is not giving up - he thinks Hachiman is a worthy rival and is on good terms with him) some time in the future.

The "biggest liar" therefore may also be Hachiman's unwillingness to accept changes, just like Ebina.

If you read even deeper (combine the idea of the last two lines): what if Hachiman actually knows his solution is "a solution but not the solution", his choice to tackle the problem in a less "desirable" way may be caused by Hachiman seeing a shadow of his own situation in Ebina.



Unrelated:
Its not like things are going to get worse for him if he starts dating Yukino. Although he may not like the unwanted attention. I await for the day where Yukino walks down the hall clinging onto his arm and making him suffer from unwanted stares from everyone... although that sound like something Haruno would do instead...