making progress, losing body size, getting faster, going longer, gaining weight?

You are gaining muscle and losing fat.  Fat weighs less than muscle so your weight is actually going up.  As you continue to train, I would imagine that you will eventually start to lose weight if your caloric spend exceeds what you eat.  If not, you might want to consult a nutritionist to help you craft a good weight-loss plan.

My suggestion for now is to ignore the scale and focus on the body changes.  FWIW, I had a similar experience when I started training.  Lost 0 lbs, but 2 pants sizes. 

x2. Congrats on all your accomplishments thus far. Good luck!

Isn't tri training amazing? I also haven't lost much weight (5LBs) but my body has completely changed. I cannot wait to see what I look like by August!! I only wish I had taken a before picture so I could compare them a few months from now.

 Keep up the good work, eventually the lbs will drop off if you keep working hard.

It is really hard!  One thing you can do to help with this is to take your measurements once a month.  That'll give you an idea of how your body shape is changing.  You already have an idea of that with the change in sizes, but I like having the numbers to back it up.   

From what you have said about your wife I don't see what you are worried about.  Keep it up as many people have already said muscle weights more than fat and if you are dropping the sizes and feel better and can see muscle tone then you are doing something right!