How do you murder your No Good Cheating Husband? Glad you asked
Poison obviously. But in this day and age it's incredibly hard to poison somebody without getting caught, it's not like way back when, where you could buy a shit ton of arsenic at any old corner store
The poison of choice is ricin, very potent and found in castor beans, which you can buy as an ornamental plant, or the beans for $10 on Amazon, so pretty easy to obtain, just incredibly discreetly, bam you got your beans
Then, how to carry it out, easy enough, burrito night. Grab a can of pinto beans from the store, cook up the castor beans in water (the ricin doesn't cook out to any significant degree), then serve up your husband a delicious pinto and castor bean filled burrito, disguising the bitter taste of the beans with some good amount of spices and also some tequila to help, but not enough to make him puke
Then, sit and wait. It make take a good few hours for the symptoms to set in. Once he starts feeling ill, refuse to take your husband to the ER, "It's fine, you're just drunk/hungover. Sleep it off."
Once he finally kicks the bucket, call the ambulance, "Oh no, my poor husband is dead!"
The police investigate and find traces of ricin in his system, and possibly even digested castor beans. "Your husband was poisoned."
"It was ricin, found in castor beans. Did you perhaps feed your husband beans before he died?"
"Why yes, officer, we had burritos the night before, I served pinto beans."
"Why weren't you affected by them then?"
"Well, sir, I didn't eat any beans. They do horrible things to my stomach."
"I see ma'am. Did any of the beans look off to you? Do you have any left to show us?"
"No sir, he ate all of them. Oh this is just horrible. Do you suppose they were mixed into my can that I bought at the store?"
An investigation is launched into the store and the bean supplier, it is suspected of an error somewhere, or more sinisterly, an intentional poisoning by someone along the supply chain. All the pinto beans in the country have been recalled. Fortunately, nobody else seems to be affected
You forgot to take out life insurance on him.