Only thing I can think of is the guy is living with his mom and bringing his bar hookups home and telling his mom - "Hey, Ma. This is, uhhh, Jill (?). We're going into the basement now. See ya."

This could have been written by my in-laws. They gave up hope of their son ever getting married - he liked to date 'interesting' girls. We had been friends for years and I met a lot of his girlfriends (and he met my boyfriends over the years). They never said a word to him (while he was dating anyway) and he never had a relationship that lasted longer than a year. We got married when he was 38 and we have been together for 11 years. We talk about how their friends don't like their DIL's - and my MIL and I get along - because her son waited until he found someone he wanted to be with. It happens. Be patient- he is just trying to figure out what he wants/likes. When the right person comes along, he will know.

Your son is 33. He is a grown man making his own adult choices. At this point, unless you are ASKED, you need to trust that you raised him well. He knows what makes a good partner, right? Because you taught him that while he was growing up. He saw you in a healthy relationship, being treated with respect and giving respect, right? Honestly, that's the best we can all do. Some of our kids will still f*ck it up and marry jerks, that is true. But no amount of hand wringing over the trashy new model will stop that from happening.

Trust your son. Open your heart to whatever woman he brings home. Live you own life.