cat spraying and urination

Question
Hi.  I have 3 cats, two female and one male.  My boyfriend moved into the house with his male, 8 year old, indoor cat in March.  He was in one room for a week, used the litter box, ate, slept on his blanket from the old house, seemed to adjust wonderfully, even befriended my male cat and played and slept together with him.  Seemed too good to be true.  He even goes outside now.  After a couple months, I noticed him coming into the bedroom and spraying.  I screamed and pointed my finger fiercely, thinking I scared him to never do it again.  Then I noticed him doing it again a week later.  I did a lot of reading, cleaning, and went through the whole house with a black light, to see if there were more markings.  There were, in different locations.  I purchased a Feliway diffuser and the spray and the problem seemed to subside.  What's funny is it wasn't like the "stray cat strong odor" you smell walking outside when you know a cat was visiting.......it's actually a mild low odor liquid, thank goodness.  Then about a month ago, I noticed some dried up puddles of yellow under a cabinet in one of my bathrooms (far away from the diffuser) and it definitely was urine.  We cleaned that and blocked it off, once again thinking everything is fine for a few weeks, and tonight I come inside the house to fine a puddle on the bathroom floor.  So now it isn't just marking, it's urinating, I believe, and I'm sure it's my boyfriends cat.  So why is he doing this,?? because he does use the litter box, I've witnessed a zillion times and he also goes to the bathroom outside.  And are these expensive chemicals I'm buying working (Feliway)?  It seems so hit and miss.  I didn't think it was a medical condition, we started showing him more affection right when this started, thinking he's just jealous and demanding attention, but now I'm wondering if he needs a vet visit? Any information would help.  Thank you so much.

Answer
Hi
this does sound strange and my first reaction is that there may be a urinary tract problem as their is so much urine ie puddles.
You didn't mention if the cat was neutered, i will assuming that it is to try answer this question.

When cats urinate it is either A an urinary infection which would smell rather strong or B it is being used as a form of communication to the other cats and to make himself feel happier in his home.

I have some information about this on my website here /cat-urine.html

But my first suggestion would be to go and have him checked by a vet, the strong smell may suggest that there is a problem.

best wishes
Kate