Despite not having his supernatural sense of touch, he's learned to pay attention to his senses. That probably had a bit to do with it.

He's looking down at her when she looks up at him. An expression of concern and interest sweeps over his face. "Yeah?" he asks in a soft, husky voice.

Matt has been avoiding those three words as well despite the fact that he's fairly confident that he does love Lydia. She needn't worry about him not sharing the sentiment, but the words do still terrify him, knowing how he can be hurt by loving someone both by the person he's in love with and by others scares him. Things are different here, but his fear is still there.