Plot questions please

OKay, so Angel was undercover and was checking up on Dorf. But then was Angel also having an affair with the blond chick who died? His wife and daughter seemed to love him and hd no idea he was into the blonde.
Also, Angel went to the club one night to talk to Oleg or the other guy (dominic purcell) and they talked about something. What was that? Was Angel a bad cop after all?