I have read the questions posted here about how to deal with the situation of significant interaction terms but insignificant 'main' effects, and my main take-away is that it depends on your research question how to proceed and interpret your results.
I would appreciate your thoughts on my interpretation in the context of my research question.
Hypothesis: The relation between height and weight is stronger for males than for females.
$$Weight = a + b_1 \times Height + b_2 \times Male + b_3 \times (Height \times Male) + e$$
$b_1$ is not significantly different from zero.
$b_3$, the interaction term, is positive and significantly different from zero.
Can I conclude that I found evidence in support of my hypothesis (that the relation between height and weight is stronger for males than for females)?