I added a JRT to my home last year - he was a rescue and was fixed and approximately 3 years old. Now have a new one - under a year - also male and fixed. They seem to be getting along except for a little jealousy and a little selfishness with the toys and bones. They play well together but rest time on the lap is an issue. I have not left them together without me but they seem to like each others company. Am I too optimistic - heard they tend to fight when there are two males. They just look like they want to have fun and I wanted to teach my 3 year old to act like a dog again as he was too dependent on me for attention. Now I am lucky if I get any attention. It seems to have worked out but I am thinking my 3 year old may be a little stressed anyway.