Oh well, I'm not a spider expert, but I was wondering about all of this some time ago (adding to the fact that I have a pet spider). So. Female spiders don't always eat male ones, it mostly depends on their mood(these fellas have a HUGE range of personalities), and hostility. Sounds not too bad, but these two criteria also make a female spider eat a male BEFORE mating, either because they thought they were weak, or... Just because, for fun? BUT. It's all from pure instincts, it's hard for spiders to survive, and they don't mate for life, they're like... One-night stand fellas, but it's not like they can do anything different. A lot of spiders have bad eyesight, they can't smell and their hearing depends purely on surface vibrations, so they just CAN'T remember their mate. If speaking about the CoTL universe, I headcanon that all creatures still have something reminiscent of 'instincts', but they can suppress them, soo... Back about Shamura. Maybe, if they're really hungry after sex (if they were a receiving end), they might have thought about eating their partner... But will they do it or not... Hehehee