Self Sabotaging behavior

I asked Mike if he wanted to take next Thursday off (T-day) and spend it with me.  I got the usual runaround about work schedule and so much work to do and how both sisters and the husband will be at the house, blah blah blah.  I told him that he said to me just a few days ago "no wonder I'm single".  I suggested that he is single because he wants to be or he is self sabotaging himself or he isn't really interested in me.  I got no response of course.  He thinks I don't understand.  I see what he is doing, but I guess what I don't understand is WHY is he doing it?  I don't want to be just the booty call now and then.  I want a relationship with someone who is going to take the time to be with me.  Not this sneaking around BS.