Affective polarization is increasing in many parts of the world, and scholars have shown increasing interest in understanding why this is. Recently it has been suggested that female political representatives may mitigate mass-level affective polarization. It has been proposed that female representatives use a more "communal" leadership style and less aggressive rhetoric, which may reduce affective polarization in the electorate, but this idea has not been systematically tested. In this paper we aim to fill in this gap by studying how politicians talk about each other on social media in 23 western countries. Using a dataset of over 10 million tweets and a combination of dictionary and multilingual language models, we find that male politicians are more likely to attack political opponents representing "outgroups", and that male representatives receive more outgroup negativity. We propose that a "male hostility spiral" may explain this pattern, where politicians attack each other online for retribution – creating a negative spiral where hostility sparks hostility.