Controversial but need help

My husband is very stubborn and refuses to give a sperm sample. Iv been ttc 1.5years its hard enough getting him to have sex im lucky if i get once a day and im fed up of begging for sex. Im planning to do an <a href="https://glowing.com/glow-fertility-program">IUI</a> next cycle so my question is how can i secretly get a sperm sample for <a href="https://glowing.com/glow-fertility-program">iui</a>? Any suggestions welcome.