Well the most obvious answer is he was a virgin. But your method is possible also.   See 4 other replies

The glasses fell to the floor almost immediately after Dr. Gregory turned around and looked terrified. There definitely wasn't time for mating, and his body was still fully clothed when Cordy found it in the freezer the next day. The she-mantis just cut his head off to get him out of the way. She doesn't have to be mating to cut off heads. Those razor sharp claw things and scary teeth still work no matter what, otherwise she wouldn't have been able to fight back when Buffy was going at her with bug spray and a machete. As to the eggs under the desk, Blayne told Xander that he'd seen the she-mantis mating with/killing another guy, and she probably just put a few of those eggs at the school to diversify her babies' feeding grounds.   See 4 other replies

yes, same actor, completely different personalities.   See 2 other replies

yes, david is on bones. but he was first on Buffy   See 2 other replies