I can only imagine MP1 mistakenly attempted a check raise. This is a bad check raise because no one else is showing strength, so this checks through 80%+ of the time, esp at a passive table. Slowplaying is even worse. way worse! Got calling stations who don't fold until the river, no one else showing strength... this is the wrong time to be deceptive. Also, to call the flop you need ~3 outs, and BDFD and BDSD fall just short of that.