Professor on campus treats me indifferent?

met an amazing gay professor on campus we are both gay. I never took his class, but we became close. However, recently I have noticed some distance like no eye contact, he avoids me but does help other people even gay people. For example, we agreed to work on another project together and he held back. But he started working with other students even gay ones on campus. It took him 6 months to ask me to help. Also, I noticed around me he brags about his fiancé which is great but he brings it up a lot. He will say you know John my fiancé? I said sure! Than he tell me again and again and again. I admire it but why the need to bring it up?