ITA with you but then I do in most cases.
Something is odd about him killing her in his truck if they were supposed to be lovers. If he was so upset and really cared about her supposedly leaving him why would he discard her naked body in such a demeaning way for LE to see when they found Lisa? Even positioning her facedown in the shallow grave shows anger, rejection, and resentment to me. He could easily be covering up in case they find his semen.... with him pretending he didn't forcefully rape her. If she really was going to break it off with him I highly doubt she was in the mood for sex when telling him so. With her body being found naked I do believe he sexually assaulted her for there is no other logical reason to discard the body naked.
Like I said earlier, I really hate it when disparaging things are said by ANY suspects against their silenced victims when they have more motives to lie than anyone. He could be trying to set this up as a crime of passion case by interjecting the 'affair' into it.
If she really was under the impression he was gay then she would trust him to not make a hit on her when they went out together. It will be interesting what his friends have to say about him and if he ever mentioned having an affair with Lisa.
It will be so tragic beyond what it already is if Lisa did really trust him and felt she was safe around him.
The police will want irrefutable evidence this affair actually existed rather being in his perverted mind instead.
Yes, the toxicology report will be most interesting to see if she had any type of date rape drug in her system at the time. Her husband seemed a little taken aback that Lisa sounded so intoxicated so I don't think that is normal for her. JMO. It seems to me if they really were having an affair they would have left the restaurant/bar and gone to a motel or hotel and if it was a crime of passion it would have happened there and not in his truck. IMO