Disharmony two male cats

Question
We have two male cats and one female. The female does not enter the picture here but thought you should know about her. Stuart(age 12) is our problem. He gets along with Reba because we brought her home when she was a baby. But,Snow-Snow (age 3) adopted us and Stuart is relentless about harrassing him. There aren't really fist fights but Stuart will stalk Snow-Snow and run at him in a threatening manner. Snow is real passive and seems puzzled and bothered by all of this. Is there anyting we can do to get Stuart to accept Snow-Snow? Thanks!

Answer
Like people, cats all have their own personalities, and sometimes there are personality conflicts.  Also like people, it's impossible to make two cats get along.

Usually with time, cats will learn to at least tolerate each other.  I've had it take up to a couple years for cats to get to the point where they'll ignore each other.  Some cats remain...catty, and will have spats here and there.

The best you can do is to provide Stuart with his own things and Snow-Snow with his own things in different territories.  I'd give them each their own bowls, own bed, own litter box, own toys, and keep those belongings in separate rooms.  Once Snow-Snow establishes one place as his territory, he's going to be dominant in that area, and Stuart is much less likely to bully him there.  It may become a safe haven for Snow-Snow to retreat to if he feels threatened.  Of course, there's no cure-all, but this is what I've found has worked best for me over the years.

Also, do put Stuart on a time-out when he bothers Snow-Snow.  A half hour in a travel crate or the bathroom will suffice.  This method was recommended to me by two animal behaviorists I consulted for an aggressive Siamese, and I've used it countless times since.  I don't believe I've had a single case that time-outs have not significantly improved.