let it sit in secondary. actually, you could have let it sit in primary. in my opinion, there is no need to secondary a tripel. just leave it in primary for 4 weeks, cold-crash, then keg. that way you save yourself the trouble of sanitizing and later cleaning a second fermenter, and you also greatly reduce your risk of infection and oxidation.
belgian yeast strains can be slow to finish - get 80% of the work done in 1 week, and take another week or 2 to do the last 20%. what is your gravity right now? has it been stable?
but regardless, let it sit. you can't rush a belgian.