"Boning" (to bone) means basically "killing undead skeletons to obtain their bones". It's a term used mostly in communities based on games (namely Minecraft), where such action is possible.
Bart had flirted with Tina in the office for months. She seemed out of his league though; he probably had even placed her her on a pedestal. Yet tonight, here he was, screwing her... boning the prime cut... and she was loving it with him.
A boning marathon is an incredibly erotic time when a couple has tremendous sex for extended periods of time. A boning marathon often lasts for upwards of two hours. It takes indredible endurance from both the man and the woman. A boning marathon is often started after alot of drinking. As we all know, drunks last longer....if not forever. You can usually identify the participants of a boning marathon by their walk. They usually walk a little funny after hours and hours of hoTT sex.