Male cat peeing on clothes on floor

Question
I have a 3 year old male cat (he is one of two male cats, both neutered, both absolutely love each other), who is urinating on any clothes, bags, rugs we leave on the basement floor. Only in the basement, and only things cloth-like. I noticed it about a month ago, but wasn't sure which cat it was. This morning I witnessed the one peeing on something on the floor. He slowly sniffed around the basement for a good 5 minutes and then found his spot. I've had to throw away numerous clothes, bags, etc. that I have sniffed out. Thought I had everything up off the floor but he always finds the one thing I forget. I have a vet appt tomorrow for him to rule out Urinary infection. Any ideas?

Answer
Well,
There could be numerous reasons.  He could be just trying to "mark" his territory.  And if one is doing it, then chances are it's both of them.  He could have a urinary infection, or he may just like relieving himself on clothing.  Do you have a litter box down there?  Because that may be cause of this problem...