Huh. So, according to wiktionary, the baser has a number of, mostly slang, meanings in french and they all seem fairly appropriate.
First, there's to Kiss. But there's also "to fuck, screw", which fits the BDSM. Then there's "to prevail over someone, fuck, screw", so the other meaning of fuck, which also fits. Then there's "to break, deteriorate", which seems to fit the rapidly falling miko.