When a woman asks the speaker what love is, he answers with doubts rather than comfort. Love, he says, is reflective, a "two way busy street," and it looks better in pictures than in real life. He admits he can't tell when loving someone is enough, or when it's time to stop. These lines sound weary, as if he has thought about love a lot and trusted it very little.
The turn comes when she seems to want him to say "I love you." He points out that it takes only eight letters, but says he would be lying. Instead he calls himself a time bomb, counting down to the moment he destroys everything near him. The mood is tense and sad. He isn't being cold; the poem suggests he refuses the easy words because he fears he will hurt her. His honesty is a kind of protection, though it also leaves her without the reassurance she asked for.