Males that won't mate

[Se_Steve]

This is my 3rd year breeding beardies. 1st year I acquired a male but he would never mate.2nd year I acquired another male and he mated the first few weeks that I had him . This year he won't mate. He came out of brumation the last week of December. Seems like they get lazy when they stay with me. Males are housed in separate enclosure unless I want them to mate. Just thought that someone could shed some light on my situation that I may doing wrong. Thanks Steve