Kenny is your boyfriend, and you are cooperating with his rival company. You are now helping outsiders instead of supporting your close one. Be careful, he might be angry with you.
We got scooped by our competitor in the race to sell the same product. What a bad move for us!
Examples (Wiktionary)
Mandarin
他们和土豪劣绅是死对头,他们毫不迟疑地向土豪劣绅营垒进攻。
他們和土豪劣紳是死對頭,他們毫不遲疑地向土豪劣紳營壘進攻。
tā men hé tǔ háo liè shēn shì sǐ duì tou , tā men háo bù chí yí de xiàng tǔ háo liè shēn yíng lěi jìn gōng .
They are deadly enemies of the camp of the local tyrants and evil gentry and attack it without the slightest hesitation.